Zoom optical system, optical apparatus, imaging apparatus and method for manufacturing the zoom optical system

ABSTRACT

A zoom optical system comprises, in order from an object: a front lens group (GFS) having a positive refractive power; an M 1  lens group (GM 1 ) having a negative refractive power; an M 2  lens group (GM 2 ) having a positive refractive power; an RN lens group (GRN) having a negative refractive power; and a subsequent lens group (GRS). Upon zooming, the distance between the front lens group (GFS) and the M 1  lens group (GM 1 ) changes, the distance between the M 1  lens group (GM 1 ) and the M 2  lens group (GM 2 ) changes, and the distance between the M 2  lens group (GM 2 ) and the RN lens group (GRN) changes. Upon focusing from an infinite distant object to a short distant object, the RN lens group (GRN) moves.

TECHNICAL FIELD

The present invention relates to a zoom optical system, an opticalapparatus and an imaging apparatus including the same, and a method formanufacturing the zoom optical system.

TECHNICAL BACKGROUND

Conventionally, zoom optical systems suitable for photographic cameras,electronic still cameras, video cameras and the like have been proposed(for example, see Patent literature 1).

PRIOR ARTS LIST Patent Document

Patent literature 1: Japanese Laid-Open Patent Publication No.H4-293007(A)

Unfortunately, according to the conventional zoom optical system,reduction in the weight of a focusing lens group is insufficient.

SUMMARY OF THE INVENTION

A zoom optical system according to the present invention comprises, inorder from an object: a front lens group having a positive refractivepower; an M1 lens group having a negative refractive power; an M2 lensgroup having a positive refractive power; an RN lens group having anegative refractive power; and a subsequent lens group, wherein uponzooming, a distance between the front lens group and the M1 lens groupchanges, a distance between the M1 lens group and the M2 lens groupchanges, and a distance between the M2 lens group and the RN lens groupchanges, and upon focusing from an infinite distant object to a shortdistant object, the RN lens group moves.

An optical apparatus according to the present invention comprises thezoom optical system.

An imaging apparatus according to the present invention comprises: thezoom optical system; and an imaging unit that takes an image formed bythe zoom optical system.

A method according to the present invention for manufacturing a zoomoptical system comprising, in order from an object, a front lens grouphaving a positive refractive power, an M1 lens group having a negativerefractive power, an M2 lens group having a positive refractive power,an RN lens group having a negative refractive power, and a subsequentlens group, comprises achieving an arrangement where upon zooming, adistance between the front lens group and the M1 lens group changes, adistance between the M1 lens group and the M2 lens group changes, and adistance between the M2 lens group and the RN lens group changes,wherein upon focusing from an infinite distant object to a short distantobject, the RN lens group moves, the subsequent lens group comprises, inorder from the object, a lens having a negative refractive power and alens having a positive refractive power, and a following conditionalexpression is satisfied,0.70<(−fN)/fP<2.00

-   -   where    -   fN: a focal length of a lens having a strongest negative        refractive power in the subsequent lens group, and    -   fP: a focal length of a lens having a strongest positive        refractive power in the subsequent lens group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a lens configuration of a zoom optical system according toa first example of this embodiment;

FIG. 2A is graphs showing various aberrations of the zoom optical systemaccording to the first example upon focusing on infinity in thewide-angle end state, and FIG. 2B is graphs showing meridional lateralaberrations (coma aberrations) when blur correction is applied to arotational blur by 0.30°;

FIG. 3 is graphs showing various aberrations of the zoom optical systemaccording to the first example upon focusing on infinity in theintermediate focal length state;

FIG. 4A is graphs showing various aberrations of the zoom optical systemaccording to the first example upon focusing on infinity in thetelephoto end state, and FIG. 4B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 5A, 5B and 5C are graphs showing various aberrations of the zoomoptical system according to the first example upon focusing on a shortdistant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 6 shows a lens configuration of a zoom optical system according toa second example of this embodiment;

FIG. 7A is graphs showing various aberrations of the zoom optical systemaccording to the second example upon focusing on infinity in thewide-angle end state, and FIG. 7B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 8 is graphs showing various aberrations of the zoom optical systemaccording to the second example upon focusing on infinity in theintermediate focal length state;

FIG. 9A is graphs showing various aberrations of the zoom optical systemaccording to the second example upon focusing on infinity in thetelephoto end state, and FIG. 9B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 10A, 10B and 10C are graphs showing various aberrations of thezoom optical system according to the second example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 11 shows a lens configuration of a zoom optical system according toa third example of this embodiment;

FIG. 12A is graphs showing various aberrations of the zoom opticalsystem according to the third example upon focusing on infinity in thewide-angle end state, and FIG. 12B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 13 is graphs showing various aberrations of the zoom optical systemaccording to the third example upon focusing on infinity in theintermediate focal length state;

FIG. 14A is graphs showing various aberrations of the zoom opticalsystem according to the third example upon focusing on infinity in thetelephoto end state, and FIG. 14B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 15A, 15B and 15C are graphs showing various aberrations of thezoom optical system according to the third example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 16 shows a lens configuration of a zoom optical system according toa fourth example of this embodiment;

FIG. 17A is graphs showing various aberrations of the zoom opticalsystem according to the fourth example upon focusing on infinity in thewide-angle end state, and FIG. 17B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 18 is graphs showing various aberrations of the zoom optical systemaccording to the fourth example upon focusing on infinity in theintermediate focal length state;

FIG. 19A is graphs showing various aberrations of the zoom opticalsystem according to the fourth example upon focusing on infinity in thetelephoto end state, and FIG. 19B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 20A, 20B and 20C are graphs showing various aberrations of thezoom optical system according to the fourth example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 21 shows a lens configuration of a zoom optical system according toa fifth example of this embodiment;

FIG. 22A is graphs showing various aberrations of the zoom opticalsystem according to the fifth example upon focusing on infinity in thewide-angle end state, and FIG. 22B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 23 is graphs showing various aberrations of the zoom optical systemaccording to the fifth example upon focusing on infinity in theintermediate focal length state;

FIG. 24A is graphs showing various aberrations of the zoom opticalsystem according to the fifth example upon focusing on infinity in thetelephoto end state, and FIG. 24B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 25A, 25B and 25C are graphs showing various aberrations of thezoom optical system according to the fifth example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 26 shows a lens configuration of a zoom optical system according toa sixth example of this embodiment;

FIG. 27A is graphs showing various aberrations of the zoom opticalsystem according to the sixth example upon focusing on infinity in thewide-angle end state, and FIG. 27B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 28 is graphs showing various aberrations of the zoom optical systemaccording to the sixth example upon focusing on infinity in theintermediate focal length state;

FIG. 29A is graphs showing various aberrations of the zoom opticalsystem according to the sixth example upon focusing on infinity in thetelephoto end state, and FIG. 29B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 30A, 30B and 30C are graphs showing various aberrations of thezoom optical system according to the sixth example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 31 shows a lens configuration of a zoom optical system according toa seventh example of this embodiment;

FIG. 32A is graphs showing various aberrations of the zoom opticalsystem according to the seventh example upon focusing on infinity in thewide-angle end state, and FIG. 32B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 33 is graphs showing various aberrations of the zoom optical systemaccording to the seventh example upon focusing on infinity in theintermediate focal length state;

FIG. 34A is graphs showing various aberrations of the zoom opticalsystem according to the seventh example upon focusing on infinity in thetelephoto end state, and FIG. 34B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 35A, 35B and 35C are graphs showing various aberrations of thezoom optical system according to the seventh example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 36 shows a lens configuration of a zoom optical system according toan eighth example of this embodiment;

FIG. 37A is graphs showing various aberrations of the zoom opticalsystem according to the eighth example upon focusing on infinity in thewide-angle end state, and FIG. 37B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 38 is graphs showing various aberrations of the zoom optical systemaccording to the eighth example upon focusing on infinity in theintermediate focal length state;

FIG. 39A is graphs showing various aberrations of the zoom opticalsystem according to the eighth example upon focusing on infinity in thetelephoto end state, and FIG. 39B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 40A, 40B and 40C are graphs showing various aberrations of thezoom optical system according to the eighth example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 41 shows a lens configuration of a zoom optical system according toa ninth example of this embodiment;

FIG. 42A is graphs showing various aberrations of the zoom opticalsystem according to the ninth example upon focusing on infinity in thewide-angle end state, and FIG. 42B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 43 is graphs showing various aberrations of the zoom optical systemaccording to the ninth example upon focusing on infinity in theintermediate focal length state;

FIG. 44A is graphs showing various aberrations of the zoom opticalsystem according to the ninth example upon focusing on infinity in thetelephoto end state, and FIG. 44B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 45A, 45B and 45C are graphs showing various aberrations of thezoom optical system according to the ninth example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 46 shows a lens configuration of a zoom optical system according toa tenth example of this embodiment;

FIG. 47A is graphs showing various aberrations of the zoom opticalsystem according to the tenth example upon focusing on infinity in thewide-angle end state, and FIG. 47B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.30°;

FIG. 48 is graphs showing various aberrations of the zoom optical systemaccording to the tenth example upon focusing on infinity in theintermediate focal length state;

FIG. 49A is graphs showing various aberrations of the zoom opticalsystem according to the tenth example upon focusing on infinity in thetelephoto end state, and FIG. 49B is graphs showing meridional lateralaberrations when blur correction is applied to a rotational blur by0.20°;

FIGS. 50A, 50B and 50C are graphs showing various aberrations of thezoom optical system according to the tenth example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 51 shows a lens configuration of a zoom optical system according toan eleventh example of this embodiment;

FIGS. 52A, 52B and 52C are graphs showing various aberrations of thezoom optical system according to the eleventh example upon focusing oninfinity in the wide-angle end state, the intermediate focal lengthstate, and the telephoto end state, respectively;

FIGS. 53A, 53B and 53C are graphs showing various aberrations of thezoom optical system according to the eleventh example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 54 shows a lens configuration of a zoom optical system according toa twelfth example of this embodiment;

FIGS. 55A, 55B and 55C are graphs showing various aberrations of thezoom optical system according to the twelfth example upon focusing oninfinity in the wide-angle end state, the intermediate focal lengthstate, and the telephoto end state, respectively;

FIGS. 56A, 56B and 56C are graphs showing various aberrations of thezoom optical system according to the twelfth example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively;

FIG. 57 shows a lens configuration of a zoom optical system according toa thirteenth example of this embodiment;

FIGS. 58A, 58B and 58C are graphs showing various aberrations of thezoom optical system according to the thirteenth example upon focusing oninfinity in the wide-angle end state, the intermediate focal lengthstate, and the telephoto end state, respectively;

FIGS. 59A, 59B and 59C are graphs showing various aberrations of thezoom optical system according to the thirteenth example upon focusing ona short distant object in the wide-angle end state, the intermediatefocal length state, and the telephoto end state, respectively;

FIG. 60 shows a configuration of a camera including the zoom opticalsystem according to this embodiment; and

FIG. 61 is a flowchart showing a method for manufacturing the zoomoptical system according to this embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a zoom optical system, an optical apparatus, and an imagingapparatus of this embodiment are described with reference to thedrawings. As shown in FIG. 1, a zoom optical system ZL(1) as an exampleof a zoom optical system (zoom lens) ZL according to this embodimentcomprises, in order from an object: a front lens group GFS having apositive refractive power; an M1 lens group GM1 having a negativerefractive power; an M2 lens group GM2 having a positive refractivepower; an RN lens group GRN having a negative refractive power; and asubsequent lens group GRS, wherein upon zooming, a distance between thefront lens group GFS and the M1 lens group GM1 changes, a distancebetween the M1 lens group GM1 and the M2 lens group GM2 changes, and adistance between the M2 lens group GM2 and the RN lens group GRNchanges, and upon focusing from an infinite distant object to a shortdistant object, the RN lens group GRN moves.

The zoom optical system ZL according to this embodiment may be a zoomoptical system ZL(2) shown in FIG. 6, a zoom optical system ZL(3) shownin FIG. 11, a zoom optical system ZL(4) shown in FIG. 16, a zoom opticalsystem ZL(5) shown in FIG. 21, a zoom optical system ZL(6) shown in FIG.26, a zoom optical system ZL(7) shown in FIG. 31, a zoom optical systemZL(8) shown in FIG. 36, a zoom optical system ZL(9) shown in FIG. 41, azoom optical system ZL(10) shown in FIG. 46, a zoom optical systemZL(11) shown in FIG. 51, a zoom optical system ZL(12) shown in FIG. 54,or a zoom optical system ZL(13) shown in FIG. 57.

The zoom optical system of this embodiment includes at least five lensgroups, and changes the distances between lens groups upon zooming fromthe wide-angle end state to the telephoto end state, thereby allowingfavorable aberration correction upon zooming to be facilitated. Focusingwith the RN lens group GRN can reduce the size and weight of the lensgroup for zooming. The optical apparatus, the imaging apparatus, and themethod for manufacturing the zoom optical system according to thisembodiment can also achieve analogous advantageous effects.

In this embodiment, the subsequent lens group GRS may comprise, in orderfrom the object: a lens having a negative refractive power; and a lenshaving a positive refractive power. Accordingly, various aberrationsincluding the coma aberration can be effectively corrected.

Furthermore, preferably, in the zoom optical system, a followingconditional expression (1) is satisfied,0.70<(−fN)/fP<2.00  (1)

-   -   where    -   fN: a focal length of a lens having a strongest negative        refractive power in the subsequent lens group GRS, and    -   fP: a focal length of a lens having a strongest positive        refractive power in the subsequent lens group GRS.

The conditional expression (1) described above defines the ratio of thefocal length of the lens that is nearer to the image in the subsequentlens group GRS and has the strongest negative refractive power to thefocal length of the lens that is nearer to the image in the subsequentlens group GRS and has the strongest positive refractive power. Bysatisfying the conditional expression (1), various aberrations includingthe coma aberration can be effectively corrected.

If the corresponding value of the conditional expression (1) exceeds theupper limit value, the refractive power of the lens that is nearer tothe image in the focusing lens group and has a positive refractive powerbecomes strong, and the coma aberration occurs excessively. Setting ofthe upper limit value of the conditional expression (1) to 1.90 can moresecurely achieve the advantageous effects of this embodiment. To furthersecure the advantageous effects of this embodiment, it is preferablethat the upper limit value of the conditional expression (1) be 1.80.

If the corresponding value of the conditional expression (1) falls belowthe lower limit value, the refractive power of the lens that is nearerto the image in the focusing lens group and has a negative refractivepower becomes strong, and the coma aberration is excessively corrected.Setting of the lower limit value of the conditional expression (1) to0.80 can more securely achieve the advantageous effects of thisembodiment. To further secure the advantageous effects of thisembodiment, it is preferable that the lower limit value of theconditional expression (1) be 0.90.

In this embodiment, preferably, upon zooming from a wide-angle end stateto a telephoto end state, the front lens group GFS moves toward theobject. Accordingly, the entire length of the lens at the wide-angle endstate can be reduced, which facilitates reduction in the size of thezoom optical system.

In this embodiment, preferably, the RN lens group GRN comprises: atleast one lens having a positive refractive power; and at least one lenshaving a negative refractive power.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (2),0.15<(−fTM1)/f1<0.35  (2)

-   -   where    -   fTM1: a focal length of the M1 lens group GM1 in a telephoto end        state, and    -   f1: a focal length of the front lens group GFS.

The conditional expression (2) defines the ratio of the focal length ofthe M1 lens group GM1 to the focal length of the front lens group GFS inthe telephoto end state. By satisfying the conditional expression (2),various aberrations including the spherical aberration upon zooming fromthe wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (2) exceeds theupper limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the upper limit value of theconditional expression (2) to 0.33 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable that the upperlimit value of the conditional expression (2) be 0.31.

If the corresponding value of the conditional expression (2) falls belowthe lower limit value, the refractive power of the M1 lens group GM1becomes strong, and it is difficult to suppress variation in variousaberrations including the spherical aberration upon zooming from thewide-angle end to the telephoto end. Setting of the lower limit value ofthe conditional expression (2) to 0.16 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable that the lowerlimit value of the conditional expression (2) be 0.17.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (3),0.20<fTM2/f1<0.40  (3)

-   -   where    -   fTM2: a focal length of the M2 lens group GM2 in a telephoto end        state, and    -   f1: a focal length of the front lens group GFS.

The conditional expression (3) defines the ratio of the focal length ofthe M2 lens group GM2 to the focal length of the front lens group GFS inthe telephoto end state. By satisfying the conditional expression (3),various aberrations including the spherical aberration upon zooming fromthe wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (3) exceeds theupper limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the upper limit value of theconditional expression (3) to 0.37 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable that the upperlimit value of the conditional expression (3) be 0.34.

If the corresponding value of the conditional expression (3) falls belowthe lower limit value, the refractive power of the M2 lens group GM2becomes strong, and it is difficult to suppress variation in variousaberrations including the spherical aberration upon zooming from thewide-angle end to the telephoto end. Setting of the lower limit value ofthe conditional expression (3) to 0.22 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable that the lowerlimit value of the conditional expression (3) be 0.24.

In this embodiment, preferably, the system further comprises a negativemeniscus lens that has a concave surface facing the object, and isadjacent to an image side of the RN lens group GRN. Accordingly, variousaberrations including the coma aberration can be effectively corrected.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (4),1.80<f1/fw<3.50  (4)

-   -   where    -   f1: a focal length of the front lens group GFS, and    -   fw: a focal length of the zoom optical system in a wide-angle        end state.

The conditional expression (4) defines the ratio of the focal length ofthe front lens group GFS to the focal length of the zoom optical systemin the wide-angle end state. By satisfying the conditional expression(4), the size of the lens barrel can be prevented from increasing, andvarious aberrations including the spherical aberration upon zooming fromthe wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (4) exceeds theupper limit value, the refractive power of the front lens group GFSbecomes weak, and the size of lens barrel increases. Setting of theupper limit value of the conditional expression (4) to 3.30 can moresecurely achieve the advantageous effects of this embodiment. To furthersecure the advantageous effects of this embodiment, it is preferable toset the upper limit value of the conditional expression (4) to 3.10.

If the corresponding value of the conditional expression (4) falls belowthe lower limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the lower limit value of theconditional expression (4) to 1.90 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set thelower limit value of the conditional expression (4) to 2.00, and it ismore preferable to set the lower limit value of the conditionalexpression (4) to 2.10.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (5),3.70<f1/(−fTM1)<5.00  (5)

-   -   where    -   f1: a focal length of the front lens group GFS, and    -   fTM1: a focal length of the M1 lens group GM1 in a telephoto end        state.

The conditional expression (5) defines the ratio of the focal length ofthe front lens group GFS to the focal length of the M1 lens group GM1.By satisfying the conditional expression (5), various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end can be suppressed.

If the corresponding value of the conditional expression (5) exceeds theupper limit value, the refractive power of the M1 lens group GM1 becomesstrong, and it is difficult to suppress variation in various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the upper limit value of theconditional expression (5) to 4.90 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set theupper limit value of the conditional expression (5) to 4.80.

If the corresponding value of the conditional expression (5) falls belowthe lower limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the lower limit value of theconditional expression (5) to 3.90 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set thelower limit value of the conditional expression (5) to 3.95.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (6),3.20<f1/fTM2<5.00  (6)

-   -   where    -   f1: a focal length of the front lens group GFS, and    -   fTM2: a focal length of the M2 lens group GM2 in a telephoto end        state.

The conditional expression (6) defines the ratio of the focal length ofthe front lens group GFS to the focal length of the M2 lens group GM2.By satisfying the conditional expression (6), various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end can be suppressed.

If the corresponding value of the conditional expression (6) exceeds theupper limit value, the refractive power of the M2 lens group GM2 becomesstrong, and it is difficult to suppress variation in various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the upper limit value of theconditional expression (6) to 4.80 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set theupper limit value of the conditional expression (6) to 4.60.

If the corresponding value of the conditional expression (6) falls belowthe lower limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the lower limit value of theconditional expression (6) to 3.40 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set thelower limit value of the conditional expression (6) to 3.60.

In this embodiment, preferably, upon zooming, a lens group nearest tothe object in the M1 lens group GM1 is fixed with respect to an imagesurface. Accordingly, degradation in performance due to manufacturingerrors is suppressed, which can secure mass-productivity.

In this embodiment, preferably, the M2 lens group GM2 comprises avibration-proof lens group movable in a direction orthogonal to anoptical axis to correct an imaging position displacement due to a camerashake or the like. Such arrangement of the vibration-proof lens group inthe M2 lens group GM2 can effectively suppress degradation inperformance upon blur correction.

In this embodiment, preferably, the vibration-proof lens group consistsof, in order from the object: a lens having a negative refractive power;and a lens having a positive refractive power. Accordingly, degradationin performance upon blur correction can be effectively suppressed.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (7),1.00<nvrN/nvrP<1.25  (7)

-   -   where    -   nvrN: a refractive index of the lens having the negative        refractive power in the vibration-proof lens group, and    -   nvrP: a refractive index of the lens having the positive        refractive power in the vibration-proof lens group.

The conditional expression (7) defines the ratio of the refractive indexof the lens that is in the vibration-proof lens group provided in the M2lens group GM2 and has a negative refractive power to the refractiveindex of the lens that is in the vibration-proof lens group and has apositive refractive power. By satisfying the conditional expression (7),degradation in performance upon blur correction can be effectivelysuppressed.

If the corresponding value of the conditional expression (7) exceeds theupper limit value, the refractive index of the lens that is in thevibration-proof lens group and has a positive refractive powerdecreases, the decentering coma aberration caused upon blur correctionexcessively occurs, and it becomes difficult to correct the aberration.Setting of the upper limit value of the conditional expression (7) to1.22 can more securely achieve the advantageous effects of thisembodiment. To further secure the advantageous effects of thisembodiment, it is preferable that the upper limit value of theconditional expression (7) be 1.20.

If the corresponding value of the conditional expression (7) is in thisrange, the refractive index of the lens that is in the vibration-prooflens group and has a negative refractive power is appropriate, and thedecentering coma aberration upon blur correction is favorably corrected,which is preferable. Setting of the lower limit value of the conditionalexpression (7) to 1.03 can more securely achieve the advantageouseffects of this embodiment. To further secure the advantageous effectsof this embodiment, it is preferable that the lower limit value of theconditional expression (7) be 1.05.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (8),0.30<νvrN/νvrP<0.90  (8)

-   -   where    -   νvrN: an Abbe number of the lens having the negative refractive        power in the vibration-proof lens group, and    -   νvrP: an Abbe number of the lens having the positive refractive        power in the vibration-proof lens group.

The conditional expression (8) defines the ratio of the Abbe number ofthe lens that is in the vibration-proof lens group and has a negativerefractive power to the Abbe number of the lens that is in thevibration-proof lens group and has a positive refractive power. Bysatisfying the conditional expression (8), degradation in performanceupon blur correction can be effectively suppressed.

If the corresponding value of the conditional expression (8) is in thisrange, the Abbe number of the lens that is in the vibration-proof lensgroup and has a positive refractive power is appropriate, and thechromatic aberration caused upon blur correction is favorably corrected,which is preferable. Setting of the upper limit value of the conditionalexpression (8) to 0.85 can more securely achieve the advantageouseffects of this embodiment. To further secure the advantageous effectsof this embodiment, it is preferable that the upper limit value of theconditional expression (8) be 0.80.

If the corresponding value of the conditional expression (8) falls belowthe lower limit value, the Abbe number of the lens that is in thevibration-proof lens group and has a negative refractive powerdecreases, and it becomes difficult to correct the chromatic aberrationcaused upon blur correction. Setting of the lower limit value of theconditional expression (8) to 0.35 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable that the lowerlimit value of the conditional expression (8) be 0.40.

In this embodiment, preferably, the M1 lens group GM1 also comprises avibration-proof lens group movable in a direction orthogonal to anoptical axis to correct an imaging position displacement due to a camerashake or the like. In this case, preferably, the vibration-proof lensgroup consists of, in order from the object: a lens having a negativerefractive power; and a lens having a positive refractive power.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (9),0.80<nvrN/nvrP<1.00  (9)

-   -   where    -   nvrN: a refractive index of the lens having the negative        refractive power in the vibration-proof lens group, and    -   nvrP: a refractive index of the lens having the positive        refractive power in the vibration-proof lens group.

The conditional expression (9) defines the ratio of the refractive indexof the lens that is in the vibration-proof lens group provided in the M1lens group GM1 and has a negative refractive power to the refractiveindex of the lens that is in the vibration-proof lens group provided inthe M1 lens group GM1 and has a positive refractive power. By satisfyingthe conditional expression (9), degradation in performance upon blurcorrection can be effectively suppressed.

If the corresponding value of the conditional expression (9) exceeds theupper limit value, the refractive index of the lens that is in thevibration-proof lens group provided in the M1 lens group GM1 and has apositive refractive power decreases, and it becomes difficult to correctthe decentering coma aberration caused upon blur correction. Setting ofthe upper limit value of the conditional expression (9) to 0.98 can moresecurely achieve the advantageous effects of this embodiment. To furthersecure the advantageous effects of this embodiment, it is preferable toset the upper limit value of the conditional expression (9) to 0.96.

If the corresponding value of the conditional expression (9) falls belowthe lower limit value, the refractive index of the lens that is in thevibration-proof lens group provided in the M1 lens group GM1 and has anegative refractive power decreases, and it becomes difficult to correctthe decentering coma aberration caused upon blur correction. Setting ofthe lower limit value of the conditional expression (9) to 0.82 can moresecurely achieve the advantageous effects of this embodiment. To furthersecure the advantageous effects of this embodiment, it is preferable toset the lower limit value of the conditional expression (9) to 0.84.

In this embodiment, preferably, the zoom optical system satisfies afollowing conditional expression (10),1.20<νvrN/νvrP<2.40  (10)

-   -   where    -   νvrN: an Abbe number of the lens having the negative refractive        power in the vibration-proof lens group, and    -   νvrP: an Abbe number of the lens having the positive refractive        power in the vibration-proof lens group.

The conditional expression (10) defines the ratio of the Abbe number ofthe lens that is in the vibration-proof lens group provided in the M1lens group GM1 and has a negative refractive power to the Abbe number ofthe lens that is in the vibration-proof lens group provided in the M1lens group GM1 and has a positive refractive power. By satisfying theconditional expression (10), degradation in performance upon blurcorrection can be effectively suppressed.

If the corresponding value of the conditional expression (10) exceedsthe upper limit value, the Abbe number of the lens that is in thevibration-proof lens group provided in the M1 lens group GM1 and has apositive refractive power significantly decreases. Accordingly, itbecomes difficult to correct the chromatic aberration caused upon blurcorrection. Setting of the upper limit value of the conditionalexpression (10) to 2.30 can more securely achieve the advantageouseffects of this embodiment. To further secure the advantageous effectsof this embodiment, it is preferable to set the upper limit value of theconditional expression (10) to 2.20.

If the corresponding value of the conditional expression (10) fallsbelow the lower limit value, the Abbe number of the lens that is in thevibration-proof lens group provided in the M1 lens group GM1 and has anegative refractive power significantly decreases. Accordingly, itbecomes difficult to correct the chromatic aberration caused upon blurcorrection. Setting of the lower limit value of the conditionalexpression (10) to 1.30 can more securely achieve the advantageouseffects of this embodiment. To further secure the advantageous effectsof this embodiment, it is preferable to set the lower limit value of theconditional expression (10) to 1.40.

In this embodiment, preferably, the subsequent lens group GRS comprisesa lens having a positive refractive power. Accordingly, variousaberrations including the coma aberration can be effectively corrected.

In this case, preferably, the zoom optical system satisfies a followingconditional expression (2),0.15<(−fTM1)/f1<0.35  (2)

Note that the conditional expression (2) is the same as described above.The details are as described above.

Also in this case, if the corresponding value of the conditionalexpression (2) exceeds the upper limit value, the refractive power ofthe front lens group GFS becomes strong, and it is difficult to correctvarious aberrations including the spherical aberration upon zooming fromthe wide-angle end to the telephoto end. Setting of the upper limitvalue of the conditional expression (2) to 0.33 can more securelyachieve the advantageous effects of this embodiment. To further securethe advantageous effects of this embodiment, it is preferable that theupper limit value of the conditional expression (2) be 0.31.

If the corresponding value of the conditional expression (2) falls belowthe lower limit value, the refractive power of the M1 lens group GM1becomes strong, and it is difficult to suppress variation in variousaberrations including the spherical aberration upon zooming from thewide-angle end to the telephoto end. Setting of the lower limit value ofthe conditional expression (2) to 0.16 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable that the lowerlimit value of the conditional expression (2) be 0.17.

In the case described above, preferably, the zoom optical systemsatisfies a following conditional expression (3),0.20<fTM2/f1<0.40  (3)

The conditional expression (3) is the same as described above. Thedetails are as described above.

Also in this case, if the corresponding value of the conditionalexpression (3) exceeds the upper limit value, the refractive power ofthe front lens group GFS becomes strong, and it is difficult to correctvarious aberrations including the spherical aberration upon zooming fromthe wide-angle end to the telephoto end. Setting of the upper limitvalue of the conditional expression (3) to 0.37 can more securelyachieve the advantageous effects of this embodiment. To further securethe advantageous effects of this embodiment, it is preferable that theupper limit value of the conditional expression (3) be 0.34.

If the corresponding value of the conditional expression (3) falls belowthe lower limit value, the refractive power of the M2 lens group GM2becomes strong, and it is difficult to suppress variation in variousaberrations including the spherical aberration upon zooming from thewide-angle end to the telephoto end. Setting of the lower limit value ofthe conditional expression (3) to 0.22 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable that the lowerlimit value of the conditional expression (3) be 0.24.

In the case described above, preferably, the zoom optical systemsatisfies a following conditional expression (4),1.80<f1/fw<3.50  (4)

The conditional expression (4) is the same as described above. Thedetails are as described above.

Also in this case, if the corresponding value of the conditionalexpression (4) exceeds the upper limit value, the refractive power ofthe front lens group GFS becomes weak, and the size of lens barrelincreases. Setting of the upper limit value of the conditionalexpression (4) to 3.30 can more securely achieve the advantageouseffects of this embodiment. To further secure the advantageous effectsof this embodiment, it is preferable to set the upper limit value of theconditional expression (4) to 3.10.

If the corresponding value of the conditional expression (4) falls belowthe lower limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the lower limit value of theconditional expression (4) to 1.90 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set thelower limit value of the conditional expression (4) to 2.00, and it ismore preferable to set the lower limit value of the conditionalexpression (4) to 2.10.

Furthermore, in the case described above, preferably, the zoom opticalsystem satisfies a following conditional expression (5),3.70<f1/(−fTM1)<5.00  (5)

The conditional expression (5) is the same as described above. Thedetails are as described above.

Also in this case, if the corresponding value of the conditionalexpression (5) exceeds the upper limit value, the refractive power ofthe M1 lens group GM1 becomes strong, and it is difficult to suppressvariation in various aberrations including the spherical aberration uponzooming from the wide-angle end to the telephoto end. Setting of theupper limit value of the conditional expression (5) to 4.90 can moresecurely achieve the advantageous effects of this embodiment. To furthersecure the advantageous effects of this embodiment, it is preferable toset the upper limit value of the conditional expression (5) to 4.80.

If the corresponding value of the conditional expression (5) falls belowthe lower limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the lower limit value of theconditional expression (5) to 3.90 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set thelower limit value of the conditional expression (5) to 3.95.

Furthermore, in the case described above, preferably, the zoom opticalsystem satisfies a following conditional expression (6),3.20<f1/fTM2<5.00  (6)

The conditional expression (6) is the same as described above. Thedetails are as described above.

Also in this case, if the corresponding value of the conditionalexpression (6) exceeds the upper limit value, the refractive power ofthe M2 lens group GM2 becomes strong, and it is difficult to suppressvariation in various aberrations including the spherical aberration uponzooming from the wide-angle end to the telephoto end. Setting of theupper limit value of the conditional expression (6) to 4.80 can moresecurely achieve the advantageous effects of this embodiment. To furthersecure the advantageous effects of this embodiment, it is preferable toset the upper limit value of the conditional expression (6) to 4.60.

If the corresponding value of the conditional expression (6) falls belowthe lower limit value, the refractive power of the front lens group GFSbecomes strong, and it is difficult to correct various aberrationsincluding the spherical aberration upon zooming from the wide-angle endto the telephoto end. Setting of the lower limit value of theconditional expression (6) to 3.40 can more securely achieve theadvantageous effects of this embodiment. To further secure theadvantageous effects of this embodiment, it is preferable to set thelower limit value of the conditional expression (6) to 3.60.

An optical apparatus and an imaging apparatus according to thisembodiment comprise the zoom optical system having the configurationdescribed above. As a specific example, a camera (corresponding to theimaging apparatus of the invention of the present application) includingthe aforementioned zoom optical system ZL is described with reference toFIG. 60. As shown in FIG. 60, this camera 1 has a lens assemblyconfiguration including a replaceable imaging lens 2. The zoom opticalsystem having the configuration described above is provided in theimaging lens 2. That is, the imaging lens 2 corresponds to the opticalapparatus of the invention of the present application. The camera 1 is adigital camera. Light from an object (subject), not shown, is collectedby the imaging lens 2, and reaches an imaging element 3. Accordingly,the light from the subject is imaged by the imaging element 3, andrecorded as a subject image in a memory, not shown. As described above,a photographer can take an image of the subject through the camera 1.Note that this camera may be a mirrorless camera, or a single-lensreflex type camera including a quick return mirror.

According to the configuration described above, the camera 1 mountedwith the zoom optical system ZL described above in the imaging lens 2can achieve high-speed AF and silence during AF without increasing thesize of the lens barrel by reducing the size and weight of the focusinglens group. Furthermore, variation of aberrations upon zooming from thewide-angle end state to the telephoto end state, and variation ofaberrations upon focusing from an infinite distant object to a shortdistant object can be favorably suppressed, and a favorable opticalperformance can be achieved.

Subsequently, referring to FIG. 61, an overview of a method formanufacturing the aforementioned zoom optical system ZL is described.First, arrange, in order from an object, a front lens group GFS having apositive refractive power, an M1 lens group GM1 having a negativerefractive power, an M2 lens group GM2 having a positive refractivepower, an RN lens group GRN having a negative refractive power, and asubsequent lens group GRS (step ST1). Then, achieve a configuration suchthat upon zooming, a distance between the front lens group GFS and theM1 lens group GM1 changes, a distance between the M1 lens group GM1 andthe M2 lens group GM2 changes, and a distance between the M2 lens groupGM2 and the RN lens group GRN changes, (step ST2). In this case, achievea configuration such that upon focusing from an infinite distant objectto a short distant object, the RN lens group GRN moves (step ST3), andconfigure the subsequent lens group GRS to include, in order from theobject, a lens having a negative refractive power, and a lens having apositive refractive power (step ST4). Furthermore, arrange each lens soas to satisfy a predetermined conditional expression (step ST5).

EXAMPLES

Hereinafter, zoom optical systems (zoom lens) ZL according to theexamples of this embodiment are described with reference to thedrawings. FIGS. 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 54 and 57 aresectional views showing the configurations and refractive powerdistributions of the zoom optical systems ZL {ZL(1) to ZL(13)} accordingto first to thirteenth examples. At lower parts of the sectional viewsof the zoom optical systems ZL(1) to ZL(13), the movement direction ofeach lens group along the optical axis during zooming from thewide-angle end state (W) to the telephoto end state (T) is indicated bya corresponding arrow. Furthermore, the movement direction duringfocusing the focusing group GRN from infinity to a short distant objectis indicated by an arrow accompanied by characters “FOCUSING.”

FIGS. 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 54 and 57 show each lensgroup by a combination of a symbol G and a numeral or alphabet(s), andshow each lens by a combination of a symbol L and a numeral. In thiscase, to prevent the types and numbers of symbols and numerals fromincreasing and being complicated, the lens groups and the like areindicated using the combinations of symbols and numerals independentlyon an example-by-example basis. Accordingly, even though the samecombinations of symbols and numerals are used among the examples, thecombinations do not mean the same configurations.

Tables 1 to 13 are hereinafter shown below. Tables 1 to 13 are tablesrepresenting various data in the first to thirteenth examples. In eachexample, d-line (wavelength 587.562 nm) and g-line (wavelength 435.835nm) are selected as calculation targets of aberration characteristics.

In [Lens data] tables, the surface number denotes the order of opticalsurfaces from the object along a light beam traveling direction, Rdenotes the radius of curvature (a surface whose center of curvature isnearer to the image is assumed to have a positive value) of each opticalsurface, D denotes the surface distance, which is the distance on theoptical axis from each optical surface to the next optical surface (orthe image surface), nd denotes the refractive index of the material ofan optical element for the d-line, and νd denotes the Abbe number of thematerial of an optical element with reference to the d-line. The objectsurface denotes the surface of an object. “∞” of the radius of curvatureindicates a flat surface or an aperture. (Stop S) indicates an aperturestop S. The image surface indicates an image surface I. The descriptionof the air refractive index nd=1.00000 is omitted.

In [Various data] tables, f denotes the focal length of the entire zoomlens, FNO denotes the f-number, 2ω denotes the angle of view(represented in units of ° (degree); ω denotes the half angle of view),and Ymax denotes the maximum image height. TL denotes the distanceobtained by adding BF to the distance on the optical axis from the lensforefront surface to the lens last surface upon focusing on infinity. BFdenotes the distance (back focus) on the optical axis from the lens lastsurface to the image surface I upon focusing on infinity. Note thatthese values are represented for zooming states of the wide-angle end(W), the intermediate focal length (M), and the telephoto end (T).

[Variable distance data] tables show the surface distances at surfacenumbers (e.g., surface numbers 5, 13, 25 and 29 in First Example) towhich the surface distance of “Variable” in the table representing [Lensdata] correspond. This shows the surface distances in the zooming statesof the wide-angle end (W), the intermediate focal length (M) and thetelephoto end (T) upon focusing on infinity and a short distant object.

[Lens group data] tables show the starting surfaces (the surfacesnearest to the object) and the focal lengths of the first to fifth lensgroups (or the sixth lens group).

[Conditional expression corresponding value] tables show valuescorresponding to the conditional expressions (1) to (10) describedabove. Here, not all the examples necessarily correspond to all theconditional expressions. Accordingly, the values of the correspondingconditional expressions in each example are shown.

Hereinafter, for all the data values, the listed focal length f, radiusof curvature R, surface distance D, other lengths and the like aretypically represented in “mm” if not otherwise specified. However, theoptical system can exert equivalent optical performances even if beingproportionally magnified or proportionally reduced. Consequently, therepresentation is not limited thereto.

The above descriptions of the tables are common to all the examples.Hereinafter, redundant description is omitted.

First Example

The first example is described with reference to FIG. 1 and Table 1.FIG. 1 shows a lens configuration of a zoom optical system according tothe first example of this embodiment. The zoom optical system ZL(1)according to this example consists of, in order from the object: a firstlens group G1 having a positive refractive power; a second lens group G2having a negative refractive power; a third lens group G3 having apositive refractive power; a fourth lens group G4 having a negativerefractive power; and a fifth lens group G5 having a positive refractivepower. The sign (+) or (−) assigned to each lens group symbol indicatesthe refractive power of the corresponding lens group. This similarlyapplies to all the following examples.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive convexo-planar lens L11 having a convex surface facing theobject; and a positive cemented lens consisting of a negative meniscuslens L12 having a convex surface facing the object, and a positivemeniscus lens L13 having a convex surface facing the object.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive biconvex lens L22; a negative biconcave lens L23; and anegative meniscus lens L24 having a concave surface facing the object.

The third lens group G3 consists of, in order from the object: apositive cemented lens consisting of a negative meniscus lens L31 havinga convex surface facing the object, and a positive biconvex lens L32; apositive cemented lens consisting of a positive biconvex lens L33, and anegative biconcave lens L34; an aperture stop S; a negative cementedlens consisting of a negative meniscus lens L35 having a convex surfacefacing the object, and a positive biconvex lens L36; and a positivebiconvex lens L37.

The fourth lens group G4 consists of, in order from the object: apositive meniscus lens L41 having a concave surface facing the object;and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: anegative meniscus lens L51 having a concave surface facing the object;and a positive biconvex lens L52.

In the optical system according to this example, focusing from a longdistant object to a short distant object is performed by moving thefourth lens group G4 in the image surface direction.

The zoom optical system according to this example corrects the imagingposition displacement due to a camera shake or the like (vibrationproof) by moving the positive cemented lens that consists of thenegative meniscus lens L31 having the convex surface facing the objectand the positive biconvex lens L32 and is included in the third lensgroup G3 (M2 lens group GM2), in a direction orthogonal to the opticalaxis.

To correct a rotational blur with an angle θ at a lens having the focallength f of the entire system and a vibration proof coefficient K (theratio of the amount of image movement on the image forming surface tothe amount of movement of the movable lens group upon blur correction),the movable lens group for blur correction may be moved in a directionorthogonal to the optical axis by (f·tan θ)/K. At the wide-angle end inthe first example, the vibration proof coefficient is 1.65, and thefocal length is 72.1 mm. Accordingly, the amount of movement of thevibration-proof lens group to correct a rotational blur by 0.30° is 0.23mm. In the telephoto end state in the first example, the vibration proofcoefficient is 2.10, and the focal length is 292.0 mm. Accordingly, theamount of movement of the vibration-proof lens group to correct arotational blur by 0.20° is 0.49 mm.

The following Table 1 lists the values of data on the optical systemaccording to this example. In Table 1, f denotes the focal length, andBF denotes the back focus.

TABLE 1 First Example [Lens data] Surface No. R D nd νd Object surface ∞1 109.4870 4.600 1.48749 70.31 2 ∞ 0.200 3 101.1800 1.800 1.62004 36.404 49.8109 7.200 1.49700 81.61 5 385.8166 Variable 6 176.0187 1.7001.69680 55.52 7 31.3680 5.150 8 32.6087 5.500 1.78472 25.64 9 −129.76341.447 10 −415.4105 1.300 1.77250 49.62 11 34.3083 4.300 12 −33.15021.200 1.85026 32.35 13 −203.5644 Variable 14 70.9040 1.200 1.80100 34.9215 30.2785 5.900 1.64000 60.20 16 −70.1396 1.500 17 34.0885 6.0001.48749 70.31 18 −42.6106 1.300 1.80610 40.97 19 401.2557 2.700 20 ∞14.110  (Stop S) 21 350.0000 1.200 1.83400 37.18 22 30.1592 4.8001.51680 63.88 23 −94.9908 0.200 24 66.3243 2.800 1.80100 34.92 25−132.5118 Variable 26 −92.0997 2.200 1.80518 25.45 27 −44.0090 6.500 28−36.9702 1.000 1.77250 49.62 29 68.3346 Variable 30 −24.5000 1.4001.62004 36.40 31 −41.1519 0.200 32 106.0000 3.800 1.67003 47.14 33−106.0000 BF Image surface ∞ [Various data] Zooming ratio 4.05 W M T f72.1 100.0 292.0 FNO 4.49 4.86 5.88 2ω 33.96 24.48 8.44 Ymax 21.60 21.6021.60 TL 190.13 205.07 245.82 BF 39.12 46.45 67.12 [Variable distancedata] W M T W M T Short Short Short Infinity Infinity Infinity distancedistance distance d5 6.204 21.150 61.895 6.204 21.150 61.895 d13 30.00022.666 2.000 30.000 22.666 2.000 d25 2.180 3.742 3.895 2.837 4.562 5.614d29 21.418 19.856 19.703 20.761 19.036 17.984 [Lens group data] GroupStarting surface f G1 1 145.319 G2 6 −29.546 G3 14 38.298 G4 26 −48.034G5 30 324.470 [Conditional expression corresponding value] (1) (−fN)/fP= 1.266 (2) (−fTM1)/f1 = 0.203 (3) fTM2/f1 = 0.264 (4) f1/fw = 2.016 (5)f1/(−fTM1) = 4.918 (6) f−/fTM2 = 3.794 (7) nvrN/nvrP = 1.098 (8)νvrN/νvrP = 0.580

FIGS. 2A and 2B are graphs showing various aberrations of the zoomoptical system having the vibration-proof function according to thefirst example upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 3 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the first example upon focusing oninfinity in the intermediate focal length state. FIGS. 4A and 4B aregraphs showing various aberrations of the zoom optical system having thevibration-proof function according to the first example upon focusing oninfinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 5A, 5B and 5C are graphs showing variousaberrations of the zoom optical system according to the first exampleupon focusing on a short distant object in the wide-angle end state, theintermediate focal length state, and the telephoto end state,respectively.

In the aberration graphs of FIGS. 2 to 5, FNO denotes the f-number, NAdenotes the numerical aperture, and Y denotes the image height. Notethat the spherical aberration graph shows the value of the f-number orthe numerical aperture corresponding to the maximum aperture. Theastigmatism graph and the distortion graph show the maximum value of theimage height. The coma aberration graph shows the value of each imageheight. d denotes the d-line (λ=587.6 nm), and g denotes the g-line(λ=435.8 nm). In the astigmatism graph, solid lines indicate sagittalimage surfaces, and broken lines indicate meridional image surfaces.Note that symbols analogous to those in this example are used also inthe aberration graphs in the following examples.

The graphs showing various aberrations show that the zoom optical systemaccording to this example favorably corrects the various aberrations andhas excellent image forming performances from the wide-angle end stateto the telephoto end state, and further has excellent image formingperformances also upon focusing on a short distant object.

Second Example

FIG. 6 shows a lens configuration of a zoom optical system according tothe second example of the present application. The zoom optical systemaccording to this example consists of, in order from the object: a firstlens group G1 having a positive refractive power; a second lens group G2having a negative refractive power; a third lens group G3 having anegative refractive power; a fourth lens group G4 having a positiverefractive power; a fifth lens group G5 having a negative refractivepower; and a sixth lens group G6 having a positive refractive power.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 and the third lens group G3 correspond to the M1lens group GM1, the fourth lens group G4 corresponds to the M2 lensgroup GM2, the fifth lens group G5 corresponds to the RN lens group GRN,and the sixth lens group G6 corresponds to the subsequent lens groupGRS.

The first lens group G1 consists of, in order from the object: apositive convexo-planar lens L11 having a convex surface facing theobject; and a positive cemented lens consisting of a negative meniscuslens L12 having a convex surface facing the object, and a positivemeniscus lens L13 having a convex surface facing the object.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive biconvex lens L22; and a negative biconcave lens L23.

The third lens group G3 consists of a negative meniscus lens L31 havinga concave surface facing the object.

The fourth lens group G4 consists of, in order from the object: apositive cemented lens consisting of a negative meniscus lens L41 havinga convex surface facing the object, and a positive biconvex lens L42; apositive cemented lens consisting of a positive biconvex lens L43, and anegative biconcave lens L44; an aperture stop S; a negative cementedlens consisting of a negative meniscus lens L45 having a convex surfacefacing the object, and a positive biconvex lens L46; and a positivebiconvex lens L47.

The fifth lens group G5 consists of, in order from the object: apositive meniscus lens L51 having a concave surface facing the object;and a negative biconcave lens L52.

The sixth lens group G6 consists of, in order from the object: anegative meniscus lens L61 having a concave surface facing the object;and a positive biconvex lens L62.

In the optical system according to this example, focusing from a longdistant object to a short distant object is performed by moving thefifth lens group G5 in the image surface direction. The imaging positiondisplacement due to a camera shake or the like is corrected by movingthe positive cemented lens that consists of the negative meniscus lensL41 having the convex surface facing the object and the positivebiconvex lens L42 and is included in the fourth lens group G4 (M2 lensgroup GM2), in a direction orthogonal to the optical axis.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. At thewide-angle end in the second example, the vibration proof coefficient is1.66, and the focal length is 72.1 mm. Accordingly, the amount ofmovement of the vibration-proof lens group to correct a rotational blurby 0.30° is 0.23 mm. In the telephoto end state in the second example,the vibration proof coefficient is 2.10, and the focal length is 292.0mm. Accordingly, the amount of movement of the vibration-proof lensgroup to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 2 lists the values of data on the optical systemaccording to this example.

TABLE 2 Second Example [Lens data] Surface No. R D nd νd Object surface∞ 1 107.5723 4.600 1.48749 70.32 2 ∞ 0.200 3 96.9007 1.800 1.62004 36.404 47.8324 7.200 1.49700 81.61 5 361.3792 Variable 6 139.8663 1.7001.69680 55.52 7 33.7621 6.806 8 33.5312 5.500 1.78472 25.64 9 −139.83480.637 10 −492.0620 1.300 1.80400 46.60 11 35.1115 Variable 12 −34.61631.200 1.83400 37.18 13 −377.1306 Variable 14 74.8969 1.200 1.80100 34.9215 31.6202 5.900 1.64000 60.19 16 −69.0444 1.500 17 34.2668 6.0001.48749 70.32 18 −42.8334 1.300 1.80610 40.97 19 434.9585 2.700 20 ∞14.312  (Stop S) 21 350.0000 1.200 1.83400 37.18 22 30.4007 4.8001.51680 63.88 23 −98.0361 0.200 24 68.9306 2.800 1.80100 34.92 25−129.3404 Variable 26 −90.5065 2.200 1.80518 25.45 27 −44.1796 6.500 28−37.6907 1.000 1.77250 49.62 29 68.3000 Variable 30 −24.5545 1.4001.62004 36.40 31 −41.7070 0.200 32 106.0000 3.800 1.67003 47.14 33−106.0000 BF Image surface ∞ [Various data] Zooming ratio 4.05 W M T f72.1 100.0 292.0 FNO 4.53 4.89 5.88 2ω 33.98 24.48 8.44 Ymax 21.60 21.6021.60 TL 190.82 206.02 245.82 BF 39.12 46.27 66.46 [Variable distancedata] W M T W M T Short Short Short Infinity Infinity Infinity distancedistance distance d5 2.861 18.057 57.861 2.861 18.057 57.861 d11 5.7275.812 6.883 5.727 5.812 6.883 d13 30.500 23.259 2.000 30.500 23.2592.000 d25 2.246 3.634 3.634 2.888 4.436 5.329 d29 22.411 21.023 21.02321.770 20.221 19.329 [Lens group data] Group Starting surface f G1 1141.867 G2 6 −104.910 G3 12 −45.774 G4 14 38.681 G5 26 −48.266 G6 30340.779 [Conditional expression corresponding value] (1) (−fN)/fP =1.248 (2) (−fTM1)/f1 = 0.208 (3) fTM2/f1 = 0.273 (4) f1/fw = 1.968 (5)f1/(−fTM1) = 4.804 (6) f1/fTM2 = 3.668 (7) nvrN/nvrP = 1.098 (8)νvrN/νvrP = 0.580

FIGS. 7A and 7B are graphs showing various aberrations of the zoomoptical system having the vibration-proof function according to thesecond example upon focusing on infinity in the wide-angle end state,and graphs showing meridional lateral aberrations when blur correctionis applied to a rotational blur by 0.30°, respectively. FIG. 8 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the second example upon focusingon infinity in the intermediate focal length state. FIGS. 9A and 9B aregraphs showing various aberrations of the zoom optical system having thevibration-proof function according to the second example upon focusingon infinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 10A, 10B and 10C are graphs showingvarious aberrations of the zoom optical system according to the secondexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to this example favorably corrects the various aberrations andhas excellent image forming performances from the wide-angle end stateto the telephoto end state, and further has excellent image formingperformances also upon focusing on a short distant object.

Third Example

FIG. 11 shows a lens configuration of a zoom optical system according tothe third example of the present application. The zoom optical systemaccording to this example consists of, in order from the object: a firstlens group G1 having a positive refractive power; a second lens group G2having a negative refractive power; a third lens group G3 having apositive refractive power; a fourth lens group G4 having a positiverefractive power; a fifth lens group G5 having a negative refractivepower; and a sixth lens group G6 having a positive refractive power.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 and the fourth lens group G4 correspond to the M2 lensgroup GM2, the fifth lens group G5 corresponds to the RN lens group GRN,and the sixth lens group G6 corresponds to the subsequent lens groupGRS.

The first lens group G1 consists of, in order from the object: apositive convexo-planar lens L11 having a convex surface facing theobject; and a positive cemented lens consisting of a negative meniscuslens L12 having a convex surface facing the object, and a positivemeniscus lens L13 having a convex surface facing the object.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive biconvex lens L22; a negative biconcave lens L23; and anegative meniscus lens L24 having a concave surface facing the object.

The third lens group G3 consists of, in order from the object: apositive cemented lens consisting of a negative meniscus lens L31 havinga convex surface facing the object, and a positive biconvex lens L32; apositive cemented lens consisting of a positive biconvex lens L33, and anegative biconcave lens L34; and an aperture stop S.

The fourth lens group G4 consists of, in order from the object: anegative cemented lens consisting of a negative meniscus lens L41 havinga convex surface facing the object, and a positive biconvex lens L42;and a positive biconvex lens L43.

The fifth lens group G5 consists of, in order from the object: apositive meniscus lens L51 having a concave surface facing the object;and a negative biconcave lens L52.

The sixth lens group G6 consists of, in order from the object: anegative meniscus lens L61 having a concave surface facing the object;and a positive biconvex lens L62.

In the optical system according to this example, focusing from a longdistant object to a short distant object is performed by moving thefifth lens group G5 in the image surface direction. The imaging positiondisplacement due to a camera shake or the like is corrected by movingthe positive cemented lens that consists of the negative meniscus lensL31 having the convex surface facing the object and the positivebiconvex lens L32 and is included in the third lens group G3 (M2 lensgroup GM2), in a direction orthogonal to the optical axis.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. At thewide-angle end in the third example, the vibration proof coefficient is1.65, and the focal length is 72.1 mm. Accordingly, the amount ofmovement of the vibration-proof lens group to correct a rotational blurby 0.30° is 0.23 mm. In the telephoto end state in the third example,the vibration proof coefficient is 2.10, and the focal length is 292.0mm. Accordingly, the amount of movement of the vibration-proof lensgroup to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 3 lists the values of data on the optical systemaccording to this example.

TABLE 3 Third Example [Lens data] Surface No. R D nd νd Object surface ∞1 106.7563 4.600 1.48749 70.32 2 ∞ 0.200 3 99.4635 1.800 1.62004 36.40 449.2336 7.200 1.49700 81.61 5 332.7367 Variable 6 152.3830 1.700 1.6968055.52 7 31.0229 5.695 8 32.0867 5.500 1.78472 25.64 9 −139.5695 1.399 10−403.4713 1.300 1.77250 49.62 11 33.8214 4.300 12 −34.0003 1.200 1.8502632.35 13 −235.0206 Variable 14 69.3622 1.200 1.80100 34.92 15 29.84205.900 1.64000 60.19 16 −71.2277 1.500 17 34.4997 6.000 1.48749 70.32 18−43.1246 1.300 1.80610 40.97 19 382.2412 2.700 20 ∞ Variable (Stop S) 21350.0000 1.200 1.83400 37.18 22 30.6178 4.800 1.51680 63.88 23 −88.25080.200 24 66.4312 2.800 1.80100 34.92 25 −142.7832 Variable 26 −93.62062.200 1.80518 25.45 27 −44.3477 6.500 28 −37.1859 1.000 1.77250 49.62 2968.3000 Variable 30 −24.9508 1.400 1.62004 36.40 31 −42.7086 0.200 32106.0000 3.800 1.67003 47.14 33 −106.0000 BF Image surface ∞ [Variousdata] Zooming ratio 4.05 W M T f 72.1 100.0 292.0 FNO 4.49 4.85 5.88 2ω33.98 24.48 8.44 Ymax 21.60 21.60 21.60 TL 190.26 205.79 245.82 BF 39.1246.10 67.12 [Variable distance data] W M T W M T Short Short ShortInfinity Infinity Infinity distance distance distance d5 5.981 21.51061.535 5.981 21.510 61.535 d13 30.000 23.014 2.000 30.000 23.014 2.000d20 14.365 14.107 14.196 14.365 14.107 14.196 d25 2.202 3.476 3.6762.867 4.301 5.396 d29 21.004 19.988 19.700 20.339 19.163 17.979 [Lensgroup data] Group Starting surface f G1 1 145.335 G2 6 −29.607 G3 1448.974 G4 21 62.364 G5 26 −48.296 G6 30 336.791 [Conditional expressioncorresponding value] (1) (−fN)/fP = 1.253 (2) (−fTM1)/f1 = 0.204 (3)fTM2/f1 = 0.264 (4) f1/fw = 2.016 (5) f1/(−fTM1) = 4.909 (6) f1/fTM2 =3.786 (7) nvrN/nvrP = 1.098 (8) νvrN/νvrP = 0.580

FIGS. 12A and 12B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to the thirdexample upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 13 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the third example upon focusing oninfinity in the intermediate focal length state. FIGS. 14A and 14B aregraphs showing various aberrations of the zoom optical system having avibration-proof function according to the third example upon focusing oninfinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 15A, 15B and 15C are graphs showingvarious aberrations of the zoom optical system according to the thirdexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to this example favorably corrects the various aberrations andhas excellent image forming performances from the wide-angle end stateto the telephoto end state, and further has excellent image formingperformances also upon focusing on a short distant object.

Fourth Example

FIG. 16 shows a lens configuration of a zoom optical system according tothe fourth example of the present application. The zoom optical systemaccording to this example consists of, in order from the object: a firstlens group G1 having a positive refractive power; a second lens group G2having a negative refractive power; a third lens group G3 having apositive refractive power; a fourth lens group G4 having a negativerefractive power; and a fifth lens group G5 having a positive refractivepower.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive convexo-planar lens L11 having a convex surface facing theobject; and a positive cemented lens consisting of a negative meniscuslens L12 having a convex surface facing the object, and a positivemeniscus lens L13 having a convex surface facing the object.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive biconvex lens L22; a negative biconcave lens L23; and anegative meniscus lens L24 having a concave surface facing the object.

The third lens group G3 consists of, in order from the object: apositive cemented lens consisting of a negative meniscus lens L31 havinga convex surface facing the object, and a positive biconvex lens L32; apositive cemented lens consisting of a positive biconvex lens L33, and anegative biconcave lens L34; an aperture stop S; a negative cementedlens consisting of a negative meniscus lens L35 having a convex surfacefacing the object, and a positive biconvex lens L36; and a positivebiconvex lens L37.

The fourth lens group G4 consists of, in order from the object: apositive meniscus lens L41 having a concave surface facing the object;and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: anegative meniscus lens L51 having a concave surface facing the object; apositive biconvex lens L52; and a positive meniscus lens L53 having aconvex surface facing the object.

In the optical system according to this example, focusing from a longdistant object to a short distant object is performed by moving thefourth lens group G4 in the image surface direction. The imagingposition displacement due to a camera shake or the like is corrected bymoving the positive cemented lens that consists of the negative meniscuslens L31 having the convex surface facing the object and the positivebiconvex lens L32 and is included in the third lens group G3 (M2 lensgroup GM2), in a direction orthogonal to the optical axis.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. At thewide-angle end in the fourth example, the vibration proof coefficient is1.65, and the focal length is 72.1 mm. Accordingly, the amount ofmovement of the vibration-proof lens group to correct a rotational blurby 0.30° is 0.23 mm. In the telephoto end state in the fourth example,the vibration proof coefficient is 2.10, and the focal length is 292.0mm. Accordingly, the amount of movement of the vibration-proof lensgroup to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 4 lists the values of data on the optical systemaccording to this example.

TABLE 4 Fourth Example [Lens data] Surface No. R D nd νd Object surface∞ 1 109.5099 4.600 1.48749 70.32 2 ∞ 0.200 3 101.8486 1.800 1.6200436.40 4 49.8873 7.200 1.49700 81.61 5 403.0130 Variable 6 166.1577 1.7001.69680 55.52 7 31.1882 3.953 8 32.0256 5.500 1.78472 25.64 9 −139.58161.553 10 −767.2482 1.300 1.77250 49.62 11 33.9202 4.300 12 −32.83511.200 1.85026 32.35 13 −256.2484 Variable 14 69.5902 1.200 1.80100 34.9215 29.9877 5.900 1.64000 60.19 16 −70.0411 1.500 17 36.2271 6.0001.48749 70.32 18 −39.9358 1.300 1.80610 40.97 19 820.8027 2.700 20 ∞14.092  (Stop S) 21 427.1813 1.200 1.83400 37.18 22 31.7606 4.8001.51680 63.88 23 −89.4727 0.200 24 73.5865 2.800 1.80100 34.92 25−110.0493 Variable 26 −83.7398 2.200 1.80518 25.45 27 −42.9999 6.500 28−36.8594 1.000 1.77250 49.62 29 73.0622 Variable 30 −26.0662 1.4001.62004 36.4 31 −40.4068 0.200 32 143.0444 3.035 1.67003 47.14 33−220.8402 0.200 34 100.4330 2.145 1.79002 47.32 35 170.3325 BF Imagesurface ∞ [Various data] Zooming ratio 4.05 W M T f 72.1 100.0 292.0 FNO4.48 4.85 5.87 2ω 33.94 24.44 8.42 Ymax 21.60 21.60 21.60 TL 190.21205.27 245.82 BF 39.12 46.37 67.13 [Variable distance data] W M T W M TShort Short Short Infinity Infinity Infinity distance distance distanced5 5.892 20.953 61.502 5.892 20.953 61.502 d13 30.000 22.752 2.00030.000 22.752 2.000 d25 2.212 3.707 3.900 2.864 4.521 5.606 d29 21.30619.811 19.618 20.654 18.997 17.912 [Lens group data] Group Startingsurface f G1 1 145.022 G2 6 −29.562 G3 14 38.233 G4 26 −48.257 G5 30318.066 [Conditional expression corresponding value] (1) (−fN)/fP =0.947 (2) (−fTM1)/f1 = 0.204 (3) fTM2/f1 = 0.264 (4) f1/fw = 2.011 (5)f1/(−fTM1) = 4.906 (6) f1/fTM2 = 3.793 (7) nvrN/nvrP = 1.098 (8)νvrN/νvrP = 0.580

FIGS. 17A and 17B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to the fourthexample upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 18 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the fourth example upon focusingon infinity in the intermediate focal length state. FIGS. 19A and 19Bare graphs showing various aberrations of the zoom optical system havinga vibration-proof function according to the fourth example upon focusingon infinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 20A, 20B and 20C are graphs showingvarious aberrations of the zoom optical system according to the fourthexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to this example favorably corrects the various aberrations andhas excellent image forming performances from the wide-angle end stateto the telephoto end state, and further has excellent image formingperformances also upon focusing on a short distant object.

Fifth Example

The fifth example is described with reference to FIGS. 21 to 25 andTable 5. FIG. 21 shows a lens configuration of a zoom optical systemaccording to the fifth example of this embodiment. The zoom opticalsystem ZL(5) according to the fifth example consists of, in order fromthe object: a first lens group G1 having a positive refractive power; asecond lens group G2 having a negative refractive power; a third lensgroup G3 having a positive refractive power; a fourth lens group G4having a negative refractive power; and a fifth lens group G5 having apositive refractive power. Upon zooming from the wide-angle end state(W) to the telephoto end state (T), the first to fifth lens groups G1 toG5 move in the directions indicated by the respective arrows in FIG. 21.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive meniscus lens L11 having a convex surface facing the object;and a positive cemented lens consisting of a negative meniscus lens L12having a convex surface facing the object, and a positive biconvex lensL13.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive biconvex lens L22; a negative biconcave lens L23; and anegative cemented lens consisting of a negative biconcave lens L24, anda positive meniscus lens L25 having a convex surface facing the object.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; a positive cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive biconvex lens L35; and a positive biconvex lens L36.

The fourth lens group G4 consists of, in order from the object: apositive meniscus lens L41 having a concave surface facing the object;and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: anegative meniscus lens L51 having a concave surface facing the object;and a positive meniscus lens L52 having a convex surface facing theobject. An image surface I is disposed to the image side of the fifthlens group G5.

In the zoom optical system ZL(5) according to the fifth example, theentire fourth lens group G4 constitutes the focusing lens group, andfocusing from a long distant object to a short distant object isperformed by moving the entire fourth lens group G4 in the image surfacedirection. In the zoom optical system ZL(5) according to the fifthexample, the negative cemented lens, which consists of the negative lensL24 and the positive meniscus lens L25 and is included in the secondlens group G2 (M1 lens group GM1), constitutes the vibration-proof lensgroup movable in a direction perpendicular to the optical axis, andcorrects the imaging position displacement (image blur on the imagesurface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. In thewide-angle end state in the fifth example, the vibration proofcoefficient is 0.97, and the focal length is 72.1 mm. Accordingly, theamount of movement of the vibration-proof lens group to correct arotational blur by 0.30° is 0.39 mm. In the telephoto end state in thefifth example, the vibration proof coefficient is 2.01, and the focallength is 292.0 mm. Accordingly, the amount of movement of thevibration-proof lens group to correct a rotational blur by 0.20° is 0.51mm.

The following Table 5 lists the values of data on the optical systemaccording to the fifth example.

TABLE 5 Fifth Example [Lens data] Surface No. R D nd νd Object surface ∞1 121.1094 4.980 1.48749 70.31 2 474.6427 0.200 3 104.9110 1.700 1.8340037.18 4 63.9583 9.069 1.49700 81.73 5 −1816.1542 Variable 6 153.92851.000 1.83400 37.18 7 37.0130 9.180 8 41.8122 5.321 1.80518 25.45 9−148.0087 1.552 10 −153.0936 1.000 1.90366 31.27 11 74.4958 4.888 12−65.0702 1.000 1.69680 55.52 13 35.9839 3.310 1.83400 37.18 14 121.5659Variable 15 85.1793 3.534 1.80400 46.60 16 −101.3301 0.200 17 38.98905.033 1.49700 81.73 18 −62.2191 1.200 1.95000 29.37 19 378.6744 1.198 20∞ 19.885  (Stop S) 21 44.8832 1.200 1.85026 32.35 22 20.5002 4.4851.51680 63.88 23 −586.4581 0.200 24 64.4878 2.563 1.62004 36.40 25−357.2881 Variable 26 −801.6030 2.383 1.80518 25.45 27 −50.3151 1.298 28−57.1873 1.000 1.77250 49.62 29 26.1668 Variable 30 −21.0000 1.3001.77250 49.62 31 −28.8136 0.200 32 58.9647 3.137 1.62004 36.40 33524.5289 BF Image surface ∞ [Various data] Zooming ratio 4.05 W M T f72.1 99.9 292.0 FNO 4.57 4.79 5.88 2ω 33.24 23.82 8.24 Ymax 21.60 21.6021.60 TL 191.32 204.14 241.16 BF 38.52 42.04 60.52 [Variable distancedata] W M T W M T Short Short Short Infinity Infinity Infinity distancedistance distance d5 2.000 22.163 69.630 2.000 22.163 69.630 d14 41.78330.929 2.000 41.783 30.929 2.000 d25 2.000 3.259 2.000 2.462 3.867 3.166d29 14.999 13.740 14.999 14.538 13.133 13.833 [Lens group data] GroupStarting surface f G1 1 167.635 G2 6 39.933 G3 15 37.727 G4 26 −36.765G5 30 2825.740 [Conditional expression corresponding value] (1) (−fN)/fP= 1.011 (2) (−fTM1)/f1 = 0.238 (3) fTM2/f1 = 0.225 (4) f1/fw = 2.325 (5)f1/(−fTM1) = 4.198 (6) f1/fTM2 = 4.443 (9) nvrN/nvrP = 0.925 (10) νvrN/νvrP = 1.493

FIGS. 22A and 22B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to the fifthexample upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 23 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the fifth example upon focusing oninfinity in the intermediate focal length state. FIGS. 24A and 24B aregraphs showing various aberrations of the zoom optical system having avibration-proof function according to the fifth example upon focusing oninfinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 25A, 25B and 25C are graphs showingvarious aberrations of the zoom optical system according to the fifthexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to fifth example favorably corrects the various aberrationsand has excellent image forming performances from the wide-angle endstate to the telephoto end state, and further has excellent imageforming performances also upon focusing on a short distant object.

Sixth Example

The sixth example is described with reference to FIGS. 26 to 30 andTable 6. FIG. 26 shows a lens configuration of a zoom optical systemaccording to the sixth example of this embodiment. The zoom opticalsystem ZL(6) according to the sixth example consists of, in order fromthe object: a first lens group G1 having a positive refractive power; asecond lens group G2 having a negative refractive power; a third lensgroup G3 having a positive refractive power; a fourth lens group G4having a negative refractive power; and a fifth lens group G5 having anegative refractive power. Upon zooming from the wide-angle end state(W) to the telephoto end state (T), the first to fifth lens groups G1 toG5 move in the directions indicated by the respective arrows in FIG. 26.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive meniscus lens L11 having a convex surface facing the object;and a positive cemented lens consisting of a negative meniscus lens L12having a convex surface facing the object, and a positive biconvex lensL13.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive cemented lens consisting of a positive biconvex lens L22 and anegative biconcave lens L23; and a negative cemented lens consisting ofa negative biconcave lens L24, and a positive meniscus lens L25 having aconvex surface facing the object.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; a negative cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive meniscus lens L35 having a convex surface facing the object;and a positive biconvex lens L36.

The fourth lens group G4 consists of, in order from the object: apositive meniscus lens L41 having a concave surface facing the object;and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: anegative meniscus lens L51 having a concave surface facing the object;and a positive meniscus lens L52 having a convex surface facing theobject. An image surface I is disposed to the image side of the fifthlens group G5.

In the zoom optical system ZL(6) according to the sixth example, theentire fourth lens group G4 constitutes the focusing lens group, andfocusing from a long distant object to a short distant object isperformed by moving the entire fourth lens group G4 in the image surfacedirection. In the zoom optical system ZL(6) according to the sixthexample, the negative cemented lens, which consists of the negative lensL24 and the positive meniscus lens L25 and is included in the secondlens group G2 (M1 lens group GM1), constitutes the vibration-proof lensgroup movable in a direction perpendicular to the optical axis, andcorrects the imaging position displacement (image blur on the imagesurface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. In thewide-angle end state in the sixth example, the vibration proofcoefficient is 0.93, and the focal length is 72.1 mm. Accordingly, theamount of movement of the vibration-proof lens group to correct arotational blur by 0.30° is 0.41 mm. In the telephoto end state in thesixth example, the vibration proof coefficient is 1.90, and the focallength is 292.0 mm. Accordingly, the amount of movement of thevibration-proof lens group to correct a rotational blur by 0.20° is 0.54mm.

The following Table 6 lists the values of data on the optical systemaccording to the sixth example.

TABLE 6 Sixth Example [Lens data] Surface No. R D nd νd Object surface ∞1 114.5391 5.639 1.48749 70.31 2 663.8041 0.200 3 103.9783 1.700 1.8340037.18 4 62.4686 8.805 1.49700 81.73 5 −43979.1830 Variable 6 146.61521.000 1.77250 49.62 7 35.8241 11.693  8 37.5245 4.696 1.68893 31.16 9−254.6834 1.000 1.83400 37.18 10 64.6045 5.066 11 −60.5874 1.000 1.5688356.00 12 39.1203 2.952 1.75520 27.57 13 93.1442 Variable 14 92.35973.688 1.80400 46.60 15 −87.7395 0.200 16 36.8528 5.291 1.49700 81.73 17−63.3187 1.200 1.95000 29.37 18 264.8384 1.289 19 ∞ 19.911  (Stop S) 2052.0583 1.200 1.85026 32.35 21 20.7485 3.983 1.51680 63.88 22 439.34630.200 23 64.0215 2.788 1.62004 36.40 24 −130.2911 Variable 25 −343.52872.371 1.80518 25.45 26 −47.6881 1.474 27 −51.9782 1.000 1.77250 49.62 2829.6298 Variable 29 −21.0360 1.300 1.60300 65.44 30 −30.1613 0.200 3164.8879 2.981 1.57501 41.51 32 614.9077 BF Image surface ∞ [Variousdata] Zooming ratio 4.05 W M T f 72.1 99.9 292.0 FNO 4.59 4.76 5.87 2ω33.22 23.72 8.22 Ymax 21.60 21.60 21.60 TL 191.32 205.16 240.15 BF 38.5241.03 60.02 [Variable distance data] W M T W M T Short Short ShortInfinity Infinity Infinity distance distance distance d5 2.000 23.30467.717 2.000 23.304 67.717 d13 40.383 30.413 2.000 40.383 30.413 2.000d24 2.000 3.305 2.001 2.487 3.962 3.248 d28 15.588 14.284 15.587 15.10113.626 14.340 [Lens group data] Group Starting surface f G1 1 161.728 G26 −38.469 G3 14 38.469 G4 25 −39.083 G5 29 −12107.081 [Conditionalexpression corresponding value] (1) (−fN)/fP = 0.968 (2) (−fTM1)/f1 =0.238 (3) fTM2/f1 = 0.238 (4) f1/fw = 2.243 (5) f1/(−fTM1) = 4.204 (6)f1/fTM2 = 4.204 (9) nvrN/nvrP = 0.894 (10)  νvrN/νvrP = 2.031

FIGS. 27A and 27B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to the sixthexample upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 28 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the sixth example upon focusing oninfinity in the intermediate focal length state. FIGS. 29A and 29B aregraphs showing various aberrations of the zoom optical system having avibration-proof function according to the sixth example upon focusing oninfinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 30A, 30B and 30C are graphs showingvarious aberrations of the zoom optical system according to the sixthexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to sixth example favorably corrects the various aberrationsand has excellent image forming performances from the wide-angle endstate to the telephoto end state, and further has excellent imageforming performances also upon focusing on a short distant object.

Seventh Example

The seventh example is described with reference to FIGS. 31 to 35 andTable 7. FIG. 31 shows a lens configuration of a zoom optical systemaccording to the seventh example of this embodiment. The zoom opticalsystem ZL(7) according to the seventh example consists of, in order fromthe object: a first lens group G1 having a positive refractive power; asecond lens group G2 having a negative refractive power; a third lensgroup G3 having a positive refractive power; a fourth lens group G4having a negative refractive power; and a fifth lens group G5 having apositive refractive power. Upon zooming from the wide-angle end state(W) to the telephoto end state (T), the first to fifth lens groups G1 toG5 move in the directions indicated by the respective arrows in FIG. 31.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive biconvex lens L11; and a positive cemented lens consisting of anegative meniscus lens L12 having a convex surface facing the object,and a positive biconvex lens L13.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive cemented lens consisting of a positive biconvex lens L22 and anegative biconcave lens L23; and a negative cemented lens consisting ofa negative biconcave lens L24, and a positive meniscus lens L25 having aconvex surface facing the object.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; and a positive cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: apositive meniscus lens L41 having a concave surface facing the object;and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: anegative meniscus lens L51 having a concave surface facing the object;and a positive biconvex lens L52. An image surface I is disposed to theimage side of the fifth lens group G5.

In the zoom optical system ZL(7) according to the seventh example, theentire fourth lens group G4 constitutes the focusing lens group, andfocusing from a long distant object to a short distant object isperformed by moving the entire fourth lens group G4 in the image surfacedirection. In the zoom optical system ZL(7) according to the seventhexample, the negative cemented lens, which consists of the negative lensL24 and the positive meniscus lens L25 and is included in the secondlens group G2 (M1 lens group GM1), constitutes the vibration-proof lensgroup movable in a direction perpendicular to the optical axis, andcorrects the imaging position displacement (image blur on the imagesurface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. In thewide-angle end state in the seventh example, the vibration proofcoefficient is 0.96, and the focal length is 72.1 mm. Accordingly, theamount of movement of the vibration-proof lens group to correct arotational blur by 0.30° is 0.39 mm. In the telephoto end state in theseventh example, the vibration proof coefficient is 2.00, and the focallength is 292.0 mm. Accordingly, the amount of movement of thevibration-proof lens group to correct a rotational blur by 0.20° is 0.51mm.

The following Table 7 lists the values of data on the optical systemaccording to the seventh example.

TABLE 7 Seventh Example [Lens data] Surface No. R D nd νd Object surface∞ 1 268.8673 3.827 1.48749 70.31 2 −1922.6559 0.200 3 111.5860 1.7001.62004 36.40 4 61.6123 8.761 1.49700 81.73 5 −1745.4439 Variable 6124.2629 1.000 1.77250 49.62 7 34.3759 7.147 8 35.3149 5.189 1.6034238.03 9 −190.5775 1.000 1.77250 49.62 10 75.4448 4.904 11 −65.2960 1.0001.67003 47.14 12 37.2634 3.301 1.80518 25.45 13 119.9726 Variable 1480.9765 3.968 1.77250 49.62 15 −78.4621 0.200 16 33.2120 5.701 1.4970081.73 17 −56.7466 1.200 1.85026 32.35 18 108.8392 1.685 19 ∞ 18.569 (Stop S) 20 40.1917 1.200 1.85026 32.35 21 18.3878 4.752 1.54814 45.7922 −98.0255 Variable 23 −121.4042 2.367 1.75520 27.57 24 −36.6433 2.11125 −37.5895 1.000 1.77250 49.62 26 35.8631 Variable 27 −21.0000 1.3001.60311 60.69 28 −30.2149 0.200 29 95.7916 3.938 1.67003 47.14 30−115.9256 BF Image surface ∞ [Various data] Zooming ratio 4.05 W M T f72.1 99.9 292.0 ENO 4.61 4.79 5.87 2ω 33.52 23.90 8.28 Ymax 21.60 21.6021.60 TL 191.32 207.98 243.25 BF 38.52 41.37 61.52 [Variable distancedata] W M T W M T Short Short Short Infinity Infinity Infinity distancedistance distance d5 2.000 25.429 72.273 2.000 25.429 72.273 d13 43.34233.718 2.000 43.342 33.718 2.000 d22 2.000 3.210 3.710 2.512 3.900 5.147d26 19.235 18.025 17.525 18.723 17.335 16.088 [Lens group data] GroupStarting surface f G1 1 169.647 G2 6 −39.988 G3 14 38.817 G4 23 −37.515G5 27 207.702 [Conditional expression corresponding value] (1) (−fN)/fP= 1.529 (2) (−fTM1)/f1 = 0.236 (3) fTM2/f1 = 0.229 (4) f1/fw = 2.353 (5)f1/(−fTM1) = 4.242 (6) f1/fTM2 = 4.370 (9) nvrN/nvrP = 0.925 (10) νvrN/νvrP = 1.852

FIGS. 32A and 32B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to theseventh example upon focusing on infinity in the wide-angle end state,and graphs showing meridional lateral aberrations when blur correctionis applied to a rotational blur by 0.30°, respectively. FIG. 33 isgraphs showing various aberrations of the zoom optical system having thevibration-proof function according to the seventh example upon focusingon infinity in the intermediate focal length state. FIGS. 34A and 34Bare graphs showing various aberrations of the zoom optical system havinga vibration-proof function according to the seventh example uponfocusing on infinity in the telephoto end state, and graphs showingmeridional lateral aberrations when blur correction is applied to arotational blur by 0.20°, respectively. FIGS. 35A, 35B and 35C aregraphs showing various aberrations of the zoom optical system accordingto the seventh example upon focusing on a short distant object in thewide-angle end state, the intermediate focal length state, and thetelephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to seventh example favorably corrects the various aberrationsand has excellent image forming performances from the wide-angle endstate to the telephoto end state, and further has excellent imageforming performances also upon focusing on a short distant object.

Eighth Example

The eighth example is described with reference to FIGS. 36 to 40 andTable 8. FIG. 36 shows a lens configuration of a zoom optical systemaccording to the eighth example of this embodiment. The zoom opticalsystem ZL(8) according to the eighth example consists of, in order fromthe object: a first lens group G1 having a positive refractive power; asecond lens group G2 having a negative refractive power; a third lensgroup G3 having a positive refractive power; a fourth lens group G4having a negative refractive power; and a fifth lens group G5 having apositive refractive power. Upon zooming from the wide-angle end state(W) to the telephoto end state (T), the first to fifth lens groups G1 toG5 move in the directions indicated by the respective arrows in FIG. 36.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive biconvex lens L11; and a positive cemented lens consisting of anegative meniscus lens L12 having a convex surface facing the object,and a positive biconvex lens L13.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive cemented lens consisting of a positive biconvex lens L22 and anegative biconcave lens L23; and a negative cemented lens consisting ofa negative biconcave lens L24, and a positive meniscus lens L25 having aconvex surface facing the object.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; and a positive cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: apositive meniscus lens L41 having a concave surface facing the object;and a negative biconcave lens L42.

The fifth lens group G5 consists of: a negative meniscus lens L51 havinga concave surface facing the object; and a positive biconvex lens L52.An image surface I is disposed to the image side of the fifth lens groupG5.

In the zoom optical system ZL(8) according to the eighth example, thepositive meniscus lens L41 and the negative lens L42 in the fourth lensgroup G4 constitute the focusing lens group, and focusing from a longdistant object to a short distant object is performed by moving thepositive meniscus lens L41 and the negative lens L42 in the fourth lensgroup G4 in the image surface direction. In the zoom optical systemZL(8) according to the eighth example, the negative cemented lens, whichconsists of the negative lens L24 and the positive meniscus lens L25 andis included in the second lens group G2 (M1 lens group GM1), constitutesthe vibration-proof lens group movable in a direction perpendicular tothe optical axis, and corrects the imaging position displacement (imageblur on the image surface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. In thewide-angle end state in the eighth example, the vibration proofcoefficient is 1.05, and the focal length is 72.1 mm. Accordingly, theamount of movement of the vibration-proof lens group to correct arotational blur by 0.30° is 0.36 mm. In the telephoto end state in theeighth example, the vibration proof coefficient is 2.20, and the focallength is 292.0 mm. Accordingly, the amount of movement of thevibration-proof lens group to correct a rotational blur by 0.20° is 0.46mm.

The following Table 8 lists the values of data on the optical systemaccording to the eighth example.

TABLE 8 Eighth Example [Lens data] Surface No. R D nd νd Object surface∞ 1 384.8872 4.307 1.48749 70.31 2 −459.3665 0.200 3 108.5471 1.7001.62004 36.40 4 59.1633 8.722 1.49700 81.73 5 −3828.8091 Variable 6116.0785 1.000 1.77250 49.62 7 33.3782 6.789 8 34.8547 5.123 1.6476933.73 9 −166.2311 1.000 1.80400 46.60 10 68.6485 5.021 11 −58.3172 1.0001.66755 41.87 12 33.1524 3.543 1.80518 25.45 13 108.5224 Variable 1480.6236 4.111 1.77250 49.62 15 −73.7947 0.200 16 32.8485 5.846 1.4970081.73 17 −53.4390 1.200 1.85026 32.35 18 100.1735 1.748 19 ∞ 17.032 (Stop S) 20 45.6071 1.200 1.80100 34.92 21 18.9488 5.048 1.54814 45.7922 −90.5382 Variable 23 −106.0821 2.387 1.72825 28.38 24 −35.2284 2.06625 −36.8890 1.000 1.77250 49.62 26 46.9619 Variable 27 −21.5153 1.3001.60311 60.69 28 −31.7338 0.200 29 126.4587 3.612 1.77250 49.62 30−132.9868 BF Image surface ∞ [Various data] Zooming ratio 4.05 W M T f72.1 99.9 292.0 FNO 4.60 4.77 5.88 2ω 33.56 23.82 8.26 Ymax 21.60 21.6021.60 TL 192.32 210.67 244.12 BF 38.52 40.08 57.94 [Variable distancedata] W M T W M T Short Short Short Infinity Infinity Infinity distancedistance distance d5 2.000 25.713 69.580 2.000 25.713 69.580 d13 40.78332.701 2.000 40.783 32.701 2.000 d22 2.000 3.163 5.584 2.559 3.917 7.234d26 23.661 23.661 23.661 23.103 22.908 22.012 [Lens group data] GroupStarting surface f G1 1 164.404 G2 6 −37.386 G3 14 38.634 G4 23 −43.744G5 27 272.771 [Conditional expression corresponding value] (1) (−fN)/fP= 1.378 (2) (−fTM1)/f1 = 0.227 (3) fTM2/f1 = 0.235 (4) f1/fw = 2.280 (5)f1/(−fTM1) = 4.397 (6) f1/fTM2 = 4.255 (9) nvrN/nvrP = 0.924 (10) νvrN/νvrP = 1.645

FIGS. 37A and 37B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to the eighthexample upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 38 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the eighth example upon focusingon infinity in the intermediate focal length state. FIGS. 39A and 39Bare graphs showing various aberrations of the zoom optical system havinga vibration-proof function according to the eighth example upon focusingon infinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 40A, 40B and 40C are graphs showingvarious aberrations of the zoom optical system according to the eighthexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to eighth example favorably corrects the various aberrationsand has excellent image forming performances from the wide-angle endstate to the telephoto end state, and further has excellent imageforming performances also upon focusing on a short distant object.

Ninth Example

The ninth example is described with reference to FIGS. 41 to 45 andTable 9. FIG. 41 shows a lens configuration of a zoom optical systemaccording to the ninth example of this embodiment. The zoom opticalsystem ZL(9) according to the ninth example consists of, in order fromthe object: a first lens group G1 having a positive refractive power; asecond lens group G2 having a negative refractive power; a third lensgroup G3 having a positive refractive power; a fourth lens group G4having a negative refractive power; and a fifth lens group G5 having apositive refractive power. Upon zooming from the wide-angle end state(W) to the telephoto end state (T), the first to fifth lens groups G1 toG5 move in the directions indicated by the respective arrows in FIG. 41.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive biconvex lens L11; and a positive cemented lens consisting of anegative meniscus lens L12 having a convex surface facing the object,and a positive biconvex lens L13.

The second lens group G2 consists of, in order from the object: anegative meniscus lens L21 having a convex surface facing the object; apositive meniscus lens L22 having a convex surface facing the object;and a negative cemented lens consisting of a negative biconcave lensL23, and a positive meniscus lens L24 having a convex surface facing theobject.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; and a positive cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: apositive meniscus lens L41 having a concave surface facing the object;and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: anegative meniscus lens L51 having a concave surface facing the object;and a positive biconvex lens L52. An image surface I is disposed to theimage side of the fifth lens group G5.

In the zoom optical system ZL(9) according to the ninth example, theentire fourth lens group G4 constitutes the focusing lens group, andfocusing from a long distant object to a short distant object isperformed by moving the entire fourth lens group G4 in the image surfacedirection. In the zoom optical system ZL(9) according to the ninthexample, the negative cemented lens, which consists of the negative lensL23 and the positive meniscus lens L24 and is included in the secondlens group G2 (M1 lens group GM1), constitutes the vibration-proof lensgroup movable in a direction perpendicular to the optical axis, andcorrects the imaging position displacement (image blur on the imagesurface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. In thewide-angle end state in the ninth example, the vibration proofcoefficient is 1.02, and the focal length is 72.1 mm. Accordingly, theamount of movement of the vibration-proof lens group to correct arotational blur by 0.30° is 0.37 mm. In the telephoto end state in theninth example, the vibration proof coefficient is 2.10, and the focallength is 292.0 mm. Accordingly, the amount of movement of thevibration-proof lens group to correct a rotational blur by 0.20° is 0.49mm.

The following Table 9 lists the values of data on the optical systemaccording to the ninth example.

TABLE 9 Ninth Example [Lens data] Surface No. R D nd νd Object surface ∞1 494.4763 3.486 1.48749 70.31 2 −654.7200 0.200 3 104.3848 1.7001.62004 36.40 4 60.0944 8.673 1.49700 81.73 5 −2277.9468 Variable 6131.3496 1.300 1.80400 46.60 7 35.6812 7.900 8 36.7192 2.871 1.6889331.16 9 62.4101 4.726 10 −66.4912 1.000 1.70000 48.11 11 36.3174 3.4141.80518 25.45 12 127.2974 Variable 13 90.0733 3.862 1.80400 46.60 14−78.6804 0.200 15 33.8033 5.583 1.49700 81.73 16 −57.6791 1.200 1.8502632.35 17 101.7237 1.726 18 ∞ 19.598  (Stop S) 19 49.9975 1.200 1.8502632.35 20 20.1023 4.713 1.54814 45.79 21 −72.4003 Variable 22 −158.44702.458 1.71736 29.57 23 −37.7406 1.732 24 −39.9149 1.000 1.77250 49.62 2543.7406 Variable 26 −22.3495 1.300 1.69680 55.52 27 −32.8093 0.200 28139.7659 3.301 1.80610 40.97 29 −141.5832 BF Image surface ∞ [Variousdata] Zooming ratio 4.05 W M T f 72.1 99.9 292.0 FNO 4.68 4.85 5.88 2ω33.48 23.86 8.26 Ymax 21.60 21.60 21.60 TL 192.32 208.96 243.67 BF 38.3241.06 60.32 [Variable distance data] W M T W M T Short Short ShortInfinity Infinity Infinity distance distance distance d5 2.000 26.07474.834 2.000 26.074 77.834 d12 45.487 35.318 2.000 45.487 35.318 2.000d21 2.000 3.315 2.845 2.597 4.123 4.511 d25 21.171 19.856 20.326 20.57419.048 18.660 [Lens group data] Group Starting surface f G1 1 171.348 G26 −41.929 G3 13 40.969 G4 22 −45.959 G5 26 423.598 [Conditionalexpression corresponding value] (1) (−fN)/fP = 1.209 (2) (−fTM1)/f1 =0.245 (3) fTM2/f1 = 0.239 (4) f1/fw = 2.377 (5) f1/(−fTM1) = 4.087 (6)f1/fTM2 = 4.182 (9) nvrN/nvrP = 0.942 (10)  νvrN/νvrP = 1.890

FIGS. 42A and 42B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to the ninthexample upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 43 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the ninth example upon focusing oninfinity in the intermediate focal length state. FIGS. 44A and 44B aregraphs showing various aberrations of the zoom optical system having avibration-proof function according to the ninth example upon focusing oninfinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 45A, 45B and 45C are graphs showingvarious aberrations of the zoom optical system according to the ninthexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to ninth example favorably corrects the various aberrationsand has excellent image forming performances from the wide-angle endstate to the telephoto end state, and further has excellent imageforming performances also upon focusing on a short distant object.

Tenth Example

The tenth example is described with reference to FIGS. 46 to 50 andTable 10. FIG. 46 shows a lens configuration of a zoom optical systemaccording to the tenth example of this embodiment. The zoom opticalsystem ZL(10) according to the tenth example consists of, in order fromthe object: a first lens group G1 having a positive refractive power; asecond lens group G2 having a negative refractive power; a third lensgroup G3 having a positive refractive power; a fourth lens group G4having a negative refractive power; and a fifth lens group G5 having apositive refractive power. Upon zooming from the wide-angle end state(W) to the telephoto end state (T), the first to fifth lens groups G1 toG5 move in the directions indicated by the respective arrows in FIG. 46.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive cemented lens consisting of a negative meniscus lens L11 havinga convex surface facing the object, and a positive biconvex lens L12;and a positive meniscus lens L13 having a convex surface facing theobject.

The second lens group G2 consists of, in order from the object: apositive biconvex lens L21; a negative biconcave lens L22; a positivemeniscus lens L23 having a convex surface facing the object; and anegative cemented lens consisting of a negative biconcave lens L24, anda positive meniscus lens L25 having a convex surface facing the object.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; and a positive cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: apositive biconvex lens L41; and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: anegative meniscus lens L51 having a concave surface facing the object;and a positive meniscus lens L52 having a convex surface facing theobject. An image surface I is disposed to the image side of the fifthlens group G5.

In the zoom optical system ZL(10) according to the tenth example, theentire fourth lens group G4 constitutes the focusing lens group, andfocusing from a long distant object to a short distant object isperformed by moving the entire fourth lens group G4 in the image surfacedirection. In the zoom optical system ZL(10) according to the tenthexample, the negative cemented lens, which consists of the negative lensL24 and the positive meniscus lens L25 and is included in the secondlens group G2 (M1 lens group GM1), constitutes the vibration-proof lensgroup movable in a direction perpendicular to the optical axis, andcorrects the imaging position displacement (image blur on the imagesurface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens havingthe focal length f of the entire system and a vibration proofcoefficient K (the ratio of the amount of image movement on the imageforming surface to the amount of movement of the movable lens group uponblur correction), the movable lens group for blur correction is moved ina direction orthogonal to the optical axis by (f·tan θ)/K. In thewide-angle end state in the tenth example, the vibration proofcoefficient is 1.01, and the focal length is 72.1 mm. Accordingly, theamount of movement of the vibration-proof lens group to correct arotational blur by 0.30° is 0.37 mm. In the telephoto end state in thetenth example, the vibration proof coefficient is 2.10, and the focallength is 292.0 mm. Accordingly, the amount of movement of thevibration-proof lens group to correct a rotational blur by 0.20° is 0.49mm.

The following Table 10 lists the values of data on the optical systemaccording to the tenth example.

TABLE 10 Tenth Example [Lens data] Surface No. R D nd νd Object surface∞ 1 139.3408 1.700 1.64769 33.73 2 77.5654 9.455 1.49700 81.73 3−496.0322 0.200 4 144.5249 3.734 1.48749 70.31 5 357.2933 Variable 6142.3498 3.303 1.84666 23.80 7 −361.0297 1.824 8 −451.3220 1.300 1.8340037.18 9 33.3045 7.193 10 35.8308 3.147 1.71736 29.57 11 69.2532 4.718 12−63.1663 1.000 1.66755 41.87 13 34.7105 3.239 1.80518 25.45 14 102.2323Variable 15 73.7312 3.697 1.77250 49.62 16 −95.2978 0.200 17 33.55575.512 1.49700 81.73 18 −68.5312 1.200 1.90366 31.27 19 129.3820 1.534 20∞ 17.193  (Stop S) 21 40.0826 1.200 1.85026 32.35 22 17.3868 5.2681.56732 42.58 23 −141.3282 Variable 24 297.2824 2.624 1.64769 33.73 25−42.2438 0.835 26 −48.9103 1.000 1.77250 49.62 27 31.0082 Variable 28−22.3095 1.300 1.69680 55.52 29 −31.0148 0.200 30 73.8865 3.135 1.8010034.92 31 3043.5154 BF Image surface ∞ [Various data] Zooming ratio 4.05W M T f 72.1 100.0 292.0 FNO 4.65 4.93 5.88 2ω 33.24 23.86 8.28 Ymax21.60 21.60 21.60 TL 192.32 206.35 244.34 BF 38.32 42.77 60.32 [Variabledistance data] W M T W M T Short Short Short Infinity Infinity Infinitydistance distance distance d5 2.000 22.642 74.835 2.000 22.642 74.835d14 44.818 33.757 2.000 44.818 33.757 2.000 d23 2.000 3.329 2.024 2.6044.116 3.661 d27 19.472 18.143 19.448 18.869 17.356 17.812 [Lens groupdata] Group Starting surface f G1 1 176.000 G2 6 −42.283 G3 15 38.971 G424 −44.470 G5 28 381.600 [Conditional expression corresponding value](1) (−fN)/fP = 1.286 (2) (−fTM1)/f1 = 0.240 (3) fTM2/f1 = 0.221 (4)f1/fw = 2.441 (5) f1/(−fTM1) = 4.162 (6) f1/fTM2 = 4.516 (9) nvrN/nvrP =0.924 (10)  νvrN/νvrP = 1.645

FIGS. 47A and 47B are graphs showing various aberrations of the zoomoptical system having a vibration-proof function according to the tenthexample upon focusing on infinity in the wide-angle end state, andgraphs showing meridional lateral aberrations when blur correction isapplied to a rotational blur by 0.30°, respectively. FIG. 48 is graphsshowing various aberrations of the zoom optical system having thevibration-proof function according to the tenth example upon focusing oninfinity in the intermediate focal length state. FIGS. 49A and 49B aregraphs showing various aberrations of the zoom optical system having avibration-proof function according to the tenth example upon focusing oninfinity in the telephoto end state, and graphs showing meridionallateral aberrations when blur correction is applied to a rotational blurby 0.20°, respectively. FIGS. 50A, 50B and 50C are graphs showingvarious aberrations of the zoom optical system according to the tenthexample upon focusing on a short distant object in the wide-angle endstate, the intermediate focal length state, and the telephoto end state,respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to tenth example favorably corrects the various aberrationsand has excellent image forming performances from the wide-angle endstate to the telephoto end state, and further has excellent imageforming performances also upon focusing on a short distant object.

Eleventh Example

The eleventh example is described with reference to FIGS. 51, 52 and 53and Table 11. FIG. 51 shows a lens configuration of a zoom opticalsystem according to the eleventh example of this embodiment. The zoomoptical system ZL(11) according to the eleventh example consists of, inorder from the object: a first lens group G1 having a positiverefractive power; a second lens group G2 having a negative refractivepower; a third lens group G3 having a positive refractive power; afourth lens group G4 having a negative refractive power; and a fifthlens group G5 having a positive refractive power. An aperture stop S isprovided in the third lens group G3. An image surface I is provided toface the image surface side of the fifth lens group G5.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive biconvex lens L11; and a positive cemented lens consisting of anegative meniscus lens L12 having a convex surface facing the object,and a positive meniscus lens L13 having a convex surface facing theobject.

The second lens group G2 consists of, in order from the object: anegative cemented lens consisting of a negative biconcave lens L21, anda positive meniscus lens L22 having a convex surface facing the object;and a negative biconcave lens L23.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; an aperture stop S; a positive cemented lensconsisting of a positive biconvex lens L32 and a negative biconcave lensL33; a positive cemented lens consisting of a negative meniscus lens L34having a convex surface facing the object, and a positive biconvex lensL35; and a positive meniscus lens L36 having a convex surface facing theobject.

The fourth lens group G4 consists of a negative cemented lens consistingof a positive meniscus lens L41 having a concave surface facing theobject, and a negative biconcave lens L42.

The fifth lens group G5 consists of a positive biconvex lens L51.

In the optical system according to the eleventh example, focusing from along distant object to a short distant object is performed by moving thefourth lens group G4 (RN lens group GRN) in the image surface direction.Preferably, the second lens group G2 (M1 lens group GM1) constitutes thevibration-proof lens group having displacement components in the opticalaxis and a direction perpendicular to the optical axis, and performsimage blur correction (vibration proof, and camera shake correction) onthe image surface I.

The following Table 11 lists the values of data on the optical systemaccording to the eleventh example.

TABLE 11 Eleventh Example [Lens data] Surface No. R D nd νd Objectsurface ∞ 1 91.1552 6.167 1.51680 63.88 2 −844.6033 0.204 3 92.53571.500 1.64769 33.73 4 45.6802 6.598 1.48749 70.31 5 154.0927 Variable 6−211.4795 1.000 1.69680 55.52 7 22.5821 3.677 1.80518 25.45 8 60.36022.652 9 −46.9021 1.000 1.77250 49.62 10 299.7358 Variable 11 48.89163.796 1.69680 55.52 12 −131.4333 1.000 13 ∞ 1.000 (Stop S) 14 39.87994.932 1.69680 55.52 15 −49.6069 1.000 1.85026 32.35 16 72.3703 8.805 1757.3477 1.000 1.80100 34.92 18 18.1075 6.038 1.48749 70.31 19 −116.15860.200 20 26.5494 3.513 1.62004 36.40 21 96.5593 Variable 22 −119.70213.510 1.74950 35.25 23 −16.6839 1.000 1.69680 55.52 24 25.6230 Variable25 124.9308 2.143 1.48749 70.31 26 −480.8453 BF Image surface ∞ [Variousdata] Zooming ratio 4.12 W M T f 71.4 100.0 294.0 FNO 4.56 4.26 5.89 2ω22.82 16.04 5.46 Ymax 14.25 14.25 14.25 TL 159.32 185.24 219.32 BF 45.3239.43 70.09 [Variable distance data] W M T W M T Short Short ShortInfinity Infinity Infinity distance distance distance d5 2.881 37.56065.654 2.881 37.560 65.654 d10 29.543 26.683 2.000 29.543 26.683 2.000d21 5.002 5.002 5.002 5.295 5.470 5.772 d24 15.836 15.836 15.836 15.54315.368 15.066 [Lens group data] Group Starting surface f G1 1 146.976 G26 −31.771 G3 11 30.544 G4 22 −32.594 G5 25 203.039 [Conditionalexpression corresponding value] (2) (−fTM1)/f1 = 0.216 (3) fTM2/f1 =0.208 (4) f1/fw = 2.058 (5) f1/(−fTM1) = 4.626 (6) f1/fTM2 = 4.809

FIGS. 52A, 52B and 52C are graphs showing various aberrations of thezoom optical system according to the eleventh example upon focusing oninfinity in the wide-angle end state, the intermediate focal lengthstate, and the telephoto end state, respectively.

FIGS. 53A, 53B and 53C are graphs showing various aberrations of thezoom optical system according to the eleventh example upon focusing on ashort distant object in the wide-angle end state, the intermediate focallength state, and the telephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical systemaccording to this example favorably corrects the various aberrations andhas excellent image forming performances from the wide-angle end stateto the telephoto end state, and further has excellent image formingperformances also upon focusing on a short distant object.

Twelfth Example

The twelfth example is described with reference to FIGS. 54, 55 and 56and Table 12. FIG. 54 shows a lens configuration of a zoom opticalsystem according to the twelfth example of this embodiment. The zoomoptical system ZL(12) according to the twelfth example consists of, inorder from the object: a first lens group G1 having a positiverefractive power; a second lens group G2 having a negative refractivepower; a third lens group G3 having a positive refractive power; afourth lens group G4 having a negative refractive power; and a fifthlens group G5 having a positive refractive power.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive biconvex lens L11; and a positive cemented lens consisting of anegative meniscus lens L12 having a convex surface facing the object,and a positive meniscus lens L13 having a convex surface facing theobject.

The second lens group G2 consists of, in order from the object: anegative cemented lens consisting of a negative biconcave lens L21, anda positive meniscus lens L22 having a convex surface facing the object;and a negative biconcave lens L23.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; a positive cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive biconvex lens L35; and a positive meniscus lens L36 having aconvex surface facing the object.

The fourth lens group G4 consists of a negative cemented lens consistingof a positive meniscus lens L41 having a concave surface facing theobject, and a negative biconcave lens L42.

The fifth lens group G5 consists of a positive meniscus lens L51 havinga convex surface facing the object.

In the optical system according to the twelfth example, focusing from along distant object to a short distant object is performed by moving thefourth lens group G4 in the image surface direction. In this example,preferably, the second lens group G2 (M1 lens group GM1) constitutes thevibration-proof lens group having displacement components in the opticalaxis and a direction perpendicular to the optical axis, and performsimage blur correction (vibration proof, and camera shake correction) onthe image surface I.

The following Table 12 lists the values of data on the optical systemaccording to the twelfth example.

TABLE 12 Twelfth Example [Lens data] Surface No. R D nd νd Objectsurface ∞ 1 100.0120 5.590 1.51680 63.88 2 −356.7115 0.200 3 87.08221.500 1.62004 36.40 4 36.8924 7.184 1.51680 63.88 5 131.1594 Variable 6−122.1413 1.000 1.69680 55.52 7 20.4910 3.496 1.80518 25.45 8 49.83572.470 9 −48.8699 1.000 1.77250 49.62 10 8360.2394 Variable 11 56.67133.785 1.58913 61.22 12 −64.2309 0.200 13 35.4309 4.669 1.48749 70.31 14−48.4394 1.000 1.80100 34.92 15 159.7328 1.860 16 ∞ 16.684  (Stop S) 1757.8297 1.000 1.80100 34.92 18 19.6163 4.946 1.48749 70.31 19 −96.42040.200 20 27.1066 2.717 1.62004 36.40 21 65.2029 Variable 22 −157.11313.395 1.64769 33.73 23 −22.3553 1.000 1.56883 56.00 24 25.0407 Variable25 46.5745 2.500 1.62004 36.40 26 60.0000 Image surface ∞ [Various data]Zooming ratio 4.29 W M T f 68.6 100.0 294.0 ENO 4.69 4.72 6.10 2ω 23.7416.04 5.46 Ymax 14.25 14.25 14.25 TL 164.32 184.76 221.32 BF 38.52 38.7364.73 [Variable distance data] W M T W M T Short Short Short InfinityInfinity Infinity distance distance distance d5 4.964 31.058 63.6694.964 31.058 63.669 d10 29.909 24.050 2.000 29.909 24.050 2.000 d213.666 4.368 2.697 4.068 4.962 3.755 d24 20.866 20.163 21.834 20.46419.569 20.776 [Lens group data] Group Starting surface f G1 1 137.939 G26 −30.083 G3 11 34.644 G4 22 −42.585 G5 25 313.363 [Conditionalexpression corresponding value] (2) (−fTM1)/f1 = 0.218 (3) fTM2/f1 =0.251 (4) f1/fw = 2.011 (5) f1/(−fTM1) = 4.585 (6) f1/fTM2 = 3.982

FIGS. 55A, 55B and 55C are graphs showing various aberrations of thezoom optical system according to the twelfth example upon focusing oninfinity in the wide-angle end state, the intermediate focal lengthstate, and the telephoto end state, respectively. FIGS. 56A, 56B and 56Care graphs showing various aberrations of the zoom optical systemaccording to the twelfth example upon focusing on a short distant objectin the wide-angle end state, the intermediate focal length state, andthe telephoto end state, respectively. The graphs showing variousaberrations show that the zoom optical system according to this examplefavorably corrects the various aberrations and has excellent imageforming performances from the wide-angle end state to the telephoto endstate, and further has excellent image forming performances also uponfocusing on a short distant object.

Thirteenth Example

The thirteenth example is described with reference to FIGS. 57, 58 and59 and Table 13. FIG. 57 shows a lens configuration of a zoom opticalsystem according to the thirteenth example of this embodiment. The zoomoptical system ZL(13) according to the thirteenth example consists of,in order from the object: a first lens group G1 having a positiverefractive power; a second lens group G2 having a negative refractivepower; a third lens group G3 having a positive refractive power; afourth lens group G4 having a negative refractive power; and a fifthlens group G5 having a positive refractive power.

In relation to the embodiment described above, in this configuration,the first lens group G1 corresponds to the front lens group GFS, thesecond lens group G2 corresponds to the M1 lens group GM1, the thirdlens group G3 corresponds to the M2 lens group GM2, the fourth lensgroup G4 corresponds to the RN lens group GRN, and the fifth lens groupG5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: apositive biconvex lens L11; and a positive cemented lens consisting of anegative meniscus lens L12 having a convex surface facing the object,and a positive meniscus lens L13 having a convex surface facing theobject.

The second lens group G2 consists of, in order from the object: anegative cemented lens consisting of a negative biconcave lens L21, anda positive meniscus lens L22 having a convex surface facing the object;and a negative biconcave lens L23.

The third lens group G3 consists of, in order from the object: apositive biconvex lens L31; a positive cemented lens consisting of apositive biconvex lens L32 and a negative biconcave lens L33; anaperture stop S; a positive cemented lens consisting of a negativemeniscus lens L34 having a convex surface facing the object, and apositive biconvex lens L35; and a positive meniscus lens L36 having aconvex surface facing the object.

The fourth lens group G4 consists of: a negative cemented lensconsisting of a positive meniscus lens L41 having a concave surfacefacing the object, and a negative biconcave lens L42; and a negativemeniscus lens L43 having a convex surface facing the object.

The fifth lens group G5 consists of a positive meniscus lens L51 havinga convex surface facing the object.

In the optical system according to the thirteenth example, focusing froma long distant object to a short distant object is performed by movingthe fourth lens group G4 in the image surface direction. In thisexample, preferably, the second lens group G2 (M1 lens group GM1)constitutes the vibration-proof lens group having displacementcomponents in the optical axis and a direction perpendicular to theoptical axis, and performs image blur correction (vibration proof, andcamera shake correction) on the image surface I.

The following Table 13 lists the values of data on the optical systemaccording to the thirteenth example.

TABLE 13 Thirteenth Example [Lens data] Surface No. R D nd νd Objectsurface ∞ 1 102.5193 5.542 1.51680 63.88 2 −366.1796 0.200 3 90.40941.500 1.62004 36.40 4 37.8518 7.229 1.51680 63.88 5 144.7539 Variable 6−163.5053 1.000 1.69680 55.52 7 20.5835 3.475 1.80518 25.45 8 48.16022.598 9 −47.4086 1.000 1.77250 49.62 10 4634.3570 Variable 11 57.60943.843 1.58913 61.22 12 −66.7307 0.200 13 36.4629 4.709 1.48749 70.31 14−48.7603 1.000 1.80100 34.92 15 206.1449 1.786 16 ∞ 16.497  (Stop S) 1755.1101 1.000 1.80100 34.92 18 19.3181 4.785 1.48749 70.31 19 −100.33870.200 20 26.0254 2.707 1.62004 36.40 21 57.5286 Variable 22 −201.99703.376 1.64769 33.73 23 −22.7237 1.000 1.56883 56.00 24 29.2295 1.172 2534.9681 1.000 1.79952 42.09 26 26.1166 Variable 27 39.9439 2.135 1.6200436.40 28 60.0000 BF Image surface ∞ [Various data] Zooming ratio 4.28 WM T f 68.7 100.0 294.0 FNO 4.70 4.73 6.06 2ω 23.74 16.08 5.48 Ymax 14.2514.25 14.25 TL 164.32 184.47 221.32 BF 38.52 38.72 64.52 [Variabledistance data] W M T W M T Short Short Short Infinity Infinity Infinitydistance distance distance d5 4.000 30.052 63.492 4.000 30.052 63.492d10 30.492 24.393 2.000 30.492 24.393 2.000 d21 3.686 4.454 2.923 4.0524.994 3.907 d26 19.668 18.899 20.430 19.301 18.359 19.446 [Lens groupdata] Group Starting surface f G1 1 138.289 G2 6 −30.436 G3 11 34.256 G422 −36.764 G5 27 185.180 [Conditional expression corresponding value](2) (−fTM1)/f1 = 0.220 (3) fTM2/f1 = 0.248 (4) f1/fw = 2.013 (5)f1/(−fTM1) = 4.544 (6) f1/fTM2 = 4.037

FIGS. 58A, 58B and 58C are graphs showing various aberrations of thezoom optical system according to the thirteenth example upon focusing oninfinity in the wide-angle end state, the intermediate focal lengthstate, and the telephoto end state, respectively. FIGS. 59A, 59B and 59Care graphs showing various aberrations of the zoom optical systemaccording to the thirteenth example upon focusing on a short distantobject in the wide-angle end state, the intermediate focal length state,and the telephoto end state, respectively. The graphs showing variousaberrations show that the zoom optical system according to this examplefavorably corrects the various aberrations and has excellent imageforming performances from the wide-angle end state to the telephoto endstate, and further has excellent image forming performances also uponfocusing on a short distant object.

According to each of the examples described above, reduction in size andweight of the focusing lens group can achieve high-speed AF and silenceduring AF without increasing the size of the lens barrel, and the zoomoptical system can be achieved that favorably suppresses variation ofaberrations upon zooming from the wide-angle end state to the telephotoend state, and variation of aberrations upon focusing from an infinitedistant object to a short distant object.

Here, each of the examples described above represents a specific exampleof the invention of the present application. The invention of thepresent application is not limited thereto.

Note that the following details can be appropriately adopted in a rangewithout impairing the optical performance of the zoom optical system ofthe present application.

The five-group configurations and the six-group configurations have beendescribed as the numeric examples of the zoom optical systems of thepresent application. However, the present application is not limitedthereto. Zoom optical systems having other group configurations (forexample, seven-group ones and the like) can also be configured.Specifically, a zoom optical system having a configuration where a lensor a lens group is added to the zoom optical system of the presentapplication at a position nearest to the object or to the image surfacemay be configured. Note that the lens group indicates a portion that hasat least one lens and is separated by air distances varying uponzooming.

The lens surfaces of the lenses constituting the zoom optical system ofthe present application may be spherical surfaces, plane surfaces, oraspherical surfaces. A case where the lens surface is a sphericalsurface or a plane surface facilitates lens processing and assemblyadjustment, and can prevent the optical performance from being reducedowing to the errors in lens processing or assembly adjustment.Consequently, the case is preferable. It is also preferable becausereduction in depiction performance is small even when the image surfacedeviates. In a case where the lens surface is an aspherical surface, thesurface may be an aspherical surface made by a grinding process, a glassmold aspherical surface made by forming glass into an aspherical shapewith a mold, or a composite type aspherical surface made by formingresin provided on the glass surface into an aspherical shape. The lenssurface may be a diffractive surface. The lens may be a gradient indexlens (GRIN lens) or a plastic lens.

An antireflection film having a high transmissivity over a widewavelength range may be applied to the lens surfaces of the lensesconstituting the zoom optical system of the present application. Thisreduces flares and ghosts, and can achieve a high optical performancehaving a high contrast.

According to the configurations described above, this camera 1 mountedwith the zoom optical system according to the first example as theimaging lens 2 can achieve high-speed AF and silence during AF withoutincreasing the size of the lens barrel, by reducing the size and weightof the focusing lens group, can favorably suppresses variation ofaberrations upon zooming from the wide-angle end state to the telephotoend state, and variation of aberrations upon focusing from an infinitedistant object to a short distant object, and can achieve a favorableoptical performance. Note that possible configurations of camerasmounted with the zoom optical systems according to the second to seventhexamples described above as the imaging lens 2 can also exert theadvantageous effects analogous to those of the camera 1 described above.

EXPLANATION OF NUMERALS AND CHARACTERS

G1 First lens group G2 Second lens group G3 Third lens group G4 Fourthlens group G5 Fifth lens group GFS Front lens group GM1 M1 lens groupGM2 M2 lens group GRN RN lens group GRS Subsequent lens group I Imagesurface S Aperture stop

The invention claimed is:
 1. A zoom optical system comprising, in orderfrom an object: a front lens group having a positive refractive power;an M1 lens group having a negative refractive power; an M2 lens grouphaving a positive refractive power; an RN lens group having a negativerefractive power; and a subsequent lens group, wherein upon zooming, adistance between the front lens group and the M1 lens group changes, adistance between the M1 lens group and the M2 lens group changes, and adistance between the M2 lens group and the RN lens group changes, uponzooming, a lens group disposed closest to an image is moved, uponfocusing from an infinite distant object to a short distant object, theRN lens group moves, and following conditional expressions aresatisfied,0.15<(−fTM1)/f1<0.350.264≤fTM2/f1<0.40 where f1: a focal length of the front lens group,fTM1: a focal length of the M1 lens group in a telephoto end state, andfTM2: a focal length of the M2 lens group in a telephoto end state,wherein the RN lens group comprises: at least one lens having positiverefractive power; and at least one lens having negative refractivepower.
 2. The zoom optical system according to claim 1, wherein thesubsequent lens group comprises, in order from the object: a lens havinga negative refractive power; and a lens having a positive refractivepower.
 3. The zoom optical system according to claim 2, wherein afollowing conditional expression is satisfied,0.70<(−fN)/fP<2.00 where fN: a focal length of a lens having a strongestnegative refractive power in the subsequent lens group, and fP: a focallength of a lens having a strongest positive refractive power in thesubsequent lens group.
 4. The zoom optical system according to claim 1,wherein upon zooming from a wide-angle end state to a telephoto endstate, the front lens group moves toward the object.
 5. The zoom opticalsystem according to claim 1, wherein the subsequent lens group comprisesa negative meniscus lens that has a concave surface facing the object,and is adjacent to an image side of the RN lens group.
 6. The zoomoptical system according to claim 1, wherein a following conditionalexpression is satisfied,1.80<f1/fw<3.50 where f1: a focal length of the front lens group, andfw: a focal length of the zoom optical system in a wide-angle end state.7. The zoom optical system according to claim 1, wherein a followingconditional expression is satisfied,3.70<f1/(−fTM1)<5.00 where f1: a focal length of the front lens group,and fTM1: a focal length of the M1 lens group in a telephoto end state.8. The zoom optical system according to claim 1, wherein a followingconditional expression is satisfied,3.20<f1/fTM2<5.00 where f1: a focal length of the front lens group, andfTM2: a focal length of the M2 lens group in a telephoto end state. 9.The zoom optical system according to claim 1, wherein upon zooming, alens group nearest to the object in the M1 lens group is fixed withrespect to an image surface.
 10. The zoom optical system according toclaim 1, wherein the M2 lens group comprises a vibration-proof lensgroup movable in a direction orthogonal to an optical axis.
 11. The zoomoptical system according to claim 10, wherein the vibration-proof lensgroup consists of, in order from the object: a lens having a negativerefractive power; and a lens having a positive refractive power.
 12. Thezoom optical system according to claim 11, wherein a followingconditional expression is satisfied,1.00<nvrN/nvrP<1.25 where nvrN: a refractive index of the lens havingthe negative refractive power in the vibration-proof lens group, andnvrP: a refractive index of the lens having the positive refractivepower in the vibration-proof lens group.
 13. The zoom optical systemaccording to claim 11, wherein a following conditional expression issatisfied,0.30<νvrN/νvrP<0.90 where νvrN: an Abbe number of the lens having thenegative refractive power in the vibration-proof lens group, and νvrP:an Abbe number of the lens having the positive refractive power in thevibration-proof lens group.
 14. The zoom optical system according toclaim 1, wherein the M1 lens group comprises a vibration-proof lensgroup movable in a direction orthogonal to an optical axis.
 15. The zoomoptical system according to claim 14, wherein the vibration-proof lensgroup consists of, in order from the object: a lens having a negativerefractive power; and a lens having a positive refractive power.
 16. Thezoom optical system according to claim 15, wherein a followingconditional expression is satisfied,0.80<nvrN/nvrP<1.00 where nvrN: a refractive index of the lens havingthe negative refractive power in the vibration-proof lens group, andnvrP: a refractive index of the lens having the positive refractivepower in the vibration-proof lens group.
 17. The zoom optical systemaccording to claim 15, wherein a following conditional expression issatisfied,1.20<νvrN/νvrP<2.40 where νvrN: an Abbe number of the lens having thenegative refractive power in the vibration-proof lens group, and νvrP:an Abbe number of the lens having the positive refractive power in thevibration-proof lens group.
 18. An optical apparatus comprising the zoomoptical system according to claim
 1. 19. An imaging apparatuscomprising: the zoom optical system according to claim 1; and an imagingunit that takes an image formed by the zoom optical system.
 20. A zoomoptical system comprising, in order from an object: a front lens grouphaving a positive refractive power; an M1 lens group having a negativerefractive power; an M2 lens group having a positive refractive power;an RN lens group having a negative refractive power; and a subsequentlens group, wherein upon zooming, a distance between the front lensgroup and the M1 lens group changes, a distance between the M1 lensgroup and the M2 lens group changes, and a distance between the M2 lensgroup and the RN lens group changes, upon zooming, a lens group disposedclosest to an image is moved, upon focusing from an infinite distantobject to a short distant object, the RN lens group moves, thesubsequent lens group comprises a lens having a positive refractivepower, and following conditional expressions are satisfied,0.20<fTM2/f1<0.401.80<f1/fw≤2.441 where fTM2: a focal length of the M2 lens group in atelephoto end state, f1: a focal length of the front lens group, and fw:a focal length of the zoom optical system in a wide-angle end state. 21.The zoom optical system according to claim 20, wherein a followingconditional expression is satisfied,0.15<(−fTM1)/f1<0.35 where fTM1: a focal length of the M1 lens group ina telephoto end state.
 22. The zoom optical system according to claim20, wherein a following conditional expression is satisfied,3.70<f1/(−fTM1<5.00 where fTM1: a focal length of the M1 lens group in atelephoto end state.
 23. The zoom optical system according to claim 20,wherein a following conditional expression is satisfied,3.20<f1/fTM2<5.00.
 24. An optical apparatus comprising the zoom opticalsystem according to claim
 20. 25. An imaging apparatus comprising: thezoom optical system according to claim 20; and an imaging unit thattakes an image formed by the zoom optical system.
 26. A method formanufacturing a zoom optical system comprising, in order from an object,a front lens group having a positive refractive power, an M1 lens grouphaving a negative refractive power, an M2 lens group having a positiverefractive power, an RN lens group having a negative refractive power,and a subsequent lens group, the method comprising: arranging the lensgroups so that: upon zooming, a distance between the front lens groupand the M1 lens group changes, a distance between the M1 lens group andthe M2 lens group changes, and a distance between the M2 lens group andthe RN lens group changes, upon zooming, a lens group disposed closestto an image is moved, and upon focusing from an infinite distant objectto a short distant object, the RN lens group moves, the method furthercomprising one of the following features A or B, wherein the feature Acomprises: disposing each lens in a lens barrel so as to satisfyfollowing conditional expressions:0.15<(−fTM1)/f1<0.350.264≤fTM2/f1<0.40 where f1: a focal length of the front lens group,fTM1: a focal length of the M1 lens group in a telephoto end state, andfTM2: a focal length of the M2 lens group in a telephoto end state, andwherein the RN lens group comprises: at least one lens having positiverefractive power; and at least one lens having negative refractivepower, and the feature B comprises: arranging so that the subsequentlens group comprises a lens having a positive refractive power, anddisposing each lens in a lens barrel so as to satisfy followingconditional expressions:0.20<fTM2/f1<0.401.80<f1/fw≤2.441 where fTM2: a focal length of the M2 lens group in atelephoto end state, f1: a focal length of the front lens group, and fw:a focal length of the zoom optical system in a wide-angle end state.